Toàn cảnh vụ nổ tại West, TX

Devastation: Firefighters conduct search and rescue of an apartment destroyed by an explosion at a fertilizer plant in West, Texas, which could have killed 15

Tragic: As many as 75 businesses and homes in West are believed to have been destroyed by the massive blast around 8pm on Wednesday

Hunt: Search and rescue teams are now going door to door to check for people who could have been injured in the massive explosion

Wasteland: The remains of a fertilizer plant sits destroyed after the explosion on Thursday morning. Authorities do not yet know what caused the blaze

The explosion shook the ground in the small town located about 20 miles north of Waco, and around 1,300 residents have now been evacuated.
The tragedy raised fears of another U.S. terror attack just days after the Boston bombs that killed three people, and comes ahead of the 20th anniversary of the Waco siege, but Mr Swanton said the blast was more likely to be a terrible industrial accident.
'They are still getting injured folks out and they are evacuating people from their homes,' Mr Swanton said in a press conference this morning. 'At this point, we don't know a number that have been killed. ... I think we will see those fatalities increase as we get toward the morning.'

More...

• 'Daddy, please get out of here:' Chilling footage captured by a father and his child who witnessed the West, Texas explosion
• Toxic cloud threatens thousands: ENTIRE town faces evacuation over ammonium nitrate suffocation risk
• Patients with horrific burns treated on football field as hospitals are flooded with victims caught in blast
• 'The whole street is gone': Survivor tells how roof collapsed on his head then he clawed his way to safety after giant fertilizer plant blast

Swanton said a minimum of 400 emergency responders arrived at the scene on Wednesday night. Officials said they were treating it as a crime scene.
'We are not indicating that it is a crime, but we don't know,' Swanton said. 'What that means to us is that until we know that it is an industrial accident, we will work it as a crime scene. The federal Bureau of Alcohol, Tobacco, Firearms and Explosives is conducting the main investigation.'
He said there is not believed to be any hazard from smoke or air particles, and firefighters believe they have the blaze in the plant under control.

Aftermath: The remains of the the West Fertilizer Co. plant smolder in the rain on Thursday after a massive explosion on Wednesday night - which could have killed as many as 15

Blast zone: The West Fertilizer Co. is close to a school, nursing home and many residences, and up to 75 are believed to have been destroyed

Location: The town of West, which has around 2,800 residents and just three ambulances, was 'overwhelmed' by the explosion, residents said

Smoke cloud: A resident in West tweeted these pictures, adding: 'Mushroom cloud from my front yard in West right after the explosion. Pretty intense situation'

Explosion: Up to 15 people are feared dead including five volunteer firefighters after a giant explosion at a fertiliser plant wreaked devastation in the town of West, Texas, leaving hundreds with horrific injuries

ABC News reported that 179 people were hospitalized with at least 24 in critical condition, nine of whom are burn victims sent to Parkland Hospital in Dallas. At least 38 people are in serious condition in total, ABC reported.
Victims are likely to have suffered 'blast injuries' including punctured lungs, eardrums, irritated eyes and possibly wounds caused by flying shrapnel and debris. A number of people are also suffering from 'respiratory distress due to chemical inhalation', head injuries and bone fractures.
Glenn Robinson, CEO of Hillcrest Baptist Medical Center, where as many as 101 blast victims have been taken, called it a 'very, very unfortunate situation'. Patients have lacerations, orthopedic and burn injuries, he said.
'The injuries that we are seeing are very serious,' he said. 'There are a number of patients that will be going to surgery.'
He added that 10 or 12 people taken to the hospital are in critical condition, with five in intensive care. Several are undergoing surgery and more than 38 are seriously injured, but there have been no fatalities.

In addition, Providence Healthcare Network in Waco has treated 65 patients, 12 of whom have have broken bones, burns and head injuries. One patient is in critical condition, ABC News reported.

Chaos: The explosion occurred at 7.50pm on Wednesday while volunteer firefighters were responding to a fire at the plant

Overwhelming: The explosion was so large that it registered as a magnitude 2.1 earthquake and caused whole streets to 'jump', residents said

Distraught: A firefighter stands on a rail line and surveys the remains of a fertilizer plant destroyed by the explosion, which injured as many as 179

TOXIC AND FLAMMABLE: ANHYDROUS AMMONIA

The West Fertilizer facility suffered an anhydrous ammonia explosion, which is ammonia in its liquid or gas state. Anhydrous ammonia is classified as toxic and dangerous for the environment - and is extremely flammable and is capable of forming highly explosive mixtures.
If Ammonia is exposed to iodine, Nitrogen triiodide is formed - which is described as a high explosive - capable of exploding out to six miles out.
The explosion affected other parts of the fertilizer plant too - which could have accelerated the mixing of toxic materials. Anhydrous ammonia is transported as a liquid at temperatures below -28°F.
In the event of a large spill it can form a toxic vapor cloud that is heavier than air until its temperature increases.
It is corrosive to copper, silver, aluminum, zinc and alloys. It reacts with body moisture, so it may burn body tissue - skin, eyes, mouth, throat, lungs and stomach - on contact, if inhaled or swallowed.

West Mayor Tommy Muska said: 'We've got a lot of people who are hurt, and there's a lot of people, I'm sure, who aren't gonna be here tomorrow. We're gonna search for everybody. We're gonna make sure everybody's accounted for. That's the most important thing right now.'
One resident, Dr. George Smith, explained that the devastation was 'overwhelming' for the small town, which has just three ambulances.
A member of the city council, Al Vanek, said the area was 'totally decimated', while McLennan County Sheriff Parnell McNamara commented: 'It looks like a war zone with all the debris.'
Dr. Smith, said that the explosion was like an 'atomic bomb.'
The toll of devastation included 50 to 75 houses, an apartment complex with about 50 units that one state police officer said was reduced to 'a skeleton,' a middle school and the West Rest Haven Nursing Home, from which first-responders evacuated 133 patients, some in wheelchairs.
Mayor Muska said rescuers are now carrying out house-by-house search and rescue in the area around the plants.
Texas Department of Public Safety D.L. Wilson said the damage was comparable to the destruction caused by the 1995 bomb blast that destroyed the Murrah Federal Building in Oklahoma City.
Rescue efforts have been hampered due to hazardous chemicals in the air following the explosion. First responders were seen wearing respirators to protect themselves.

Emergency treatment: Victims from the West fertilizer plant explosion are wheeled into Hillcrest Baptist Medical Hospital in Waco, Texas

Makeshift treatment: Injured people being treated on the flood-lit the high school football field turned into a staging area after the blast

Desperate: School buses were used to ferry residents away from the scene of the explosion. Sergeant W. Patrick Swanton from Waco¿s police department said at least 160 people have been treated for injuries at local hospitals

The toll of devastation included 50 to 75 houses, an apartment complex with about 50 units that one state police officer said was reduced to 'a skeleton,' a middle school and the West Rest Haven Nursing Home, from which first-responders evacuated 133 patients, some in wheelchairs

A thunderstorm has been forecast, which could lead to stronger winds pushing the mist - which can cause significant irritation to eyes and skin, and cause breathing problems - around the area. Those north of the blast have been told to stay inside and keep their windows shut to stop the fumes creeping inside their homes.
Although officials have turned off all the gas, they evacuated half the town because they were worried another tank at the facility might explode.
There were subsequent explosions around 10 p.m., according to WFAA. While the cause of the explosions has not yet been reported, a dispatcher was heard in emergency audio recordings warning crews to move away from chemicals in tanks that had not exploded.
Ben Stratmann, a spokesman for Texas State Sen. Brian Birdwell, said: 'What we are hearing is that there is one fertilizer tank that is still intact at the plant, and there are evacuations in place to make sure everyone gets away from the area safely in case of another explosion,' CNN reported.

If the winds turn, the other half of the town will have to be evacuated as well.
As the small town struggles to comprehend the situation, residents and eyewitnesses have described shocking scenes of destruction.
'It's total chaos,' West City Councilwoman Cheryl Marak told ABC News. She said the explosion killed her dog and felled her home, which is about two blocks from the plant.

Blast: According to eyewitnesses firefighters were attending the blaze when there was a sudden explosion - three firefighters are dead according to authorities

Blaze: The blast ripped through West Fertilizer at 7.50pm and fires continue to burn at the scene

Search: The missing volunteer firefighters and a policeman were attending a blaze at the plant at about 7:50pm local time last night it suddenly exploded into a fireball - it thought to be caused by anhydrous ammonia igniting in the heat of the fire

Terrifying: A fire blazes in a home near to the plant - some people are thought still to be trapped in buildings and a number of firefighters are reported missing

 VIDEO  Fire, explosion and then...'Dad, I can't hear'. Heartbreaking moment girl and father film blast

'Dad I can't hear!' MOMENT of Texas fertilizer plant explosion...

'With the explosions, the whole street lifted up. It was like a massive bomb went off. It demolished both my houses, my mother's and mine. I think everything around us is pretty much just gone.'
Dr. George Smith, speaking with cuts and bloody injuries on his face, described apocalyptic scenes as the roof fell in: 'The windows came in on me, the roof came in on me, the ceiling came in and I worked my way out to go get some more help.
He told NBC News: 'Of course, we lost all communication because the power went out.
'The ambulance station is badly damaged, the whole 1500 block of Stillmeadow, which is the closest street to it.

'My son lives there - he was on the second floor when it fell down, it would have fallen on him. That whole street is gone.'
Local residents, some more than a mile away, reported windows being blown out and hearing an explosion that sounded 'like a bomb'.
Local resident Bill Bohannan told the Waco Tribune that the blast knocked him off his feet.
He said: 'I was standing next to my car with my fiancee, waiting for my parents to come out and (the plant) exploded.

Glow: The remains of a silo that was part of a fertilizer plant burns and smokes Thursday morning after the plant exploded on Wednesday night

Remains: A destroyed home burns early Thursday morning as rescue teams search for victims and go from door-to-door to check on residents who could have been hurt

Damage: Other homes and businesses lost windows in the impact of the glass in West, Texas on Wednesday night

To the rescue: Emergency workers assist an elderly person at an emergency triage area in a local school stadium in West, Texas

Evacuated: People push wheel chairs in front of the damaged nursing home, frin where 133 residents were evacuated on Wednesday night after the explosion

Destruction: Rescue workers pass a damaged apartment complex after a nearby fertilizer plant exploded in Texas

Search: The mayor of West, Tommy Muska confirmed the figure of around 160 injured people taken to hospitals

'It knocked us into the car... Every house within about four blocks is blown apart.'
Emergency audio also reveals the panic and chaos among firefighters and others at the scene, ABC reported. 'We need every ambulance we can get this way,' one dispatcher says. 'A bomb just went off. It's pretty bad.'
'Firefighters down,' another said. 'There has been an explosion.'
In the hours after the blast, many of the town's residents wandered the dark and windy streets searching for shelter.
Among them was Julie Zahirniako, who said she and her son, Anthony, had been playing at a school playground near the fertilizer plant when the explosion hit. She was walking the track, he was kicking a football.
The explosion threw her son 4 feet in the air, breaking his ribs. She said she saw people running from the nursing home and the roof of the school lifted into the air.
'The fire was so high,' she said. 'It was just as loud as it could be. The ground and everything was shaking.'

Grim: Today firefighters are painstakingly combing through houses, many reduced to rubble

Search: Firefighters use flashlights to search a destroyed apartment complex looking for residents

Precautions: Half the town has been evacuated as as a result of the explosion

Trapped: Reports said a nursing home had collapsed in the explosion and some people were believed trapped inside

Rescue: Earth moving equipment rolls through the downtown area in the middle of the night after explosion

Shudder: The blast was so massive that it registered as a magnitude 2.1 earthquake, as this graph from the US Geological Survey shows

Erick Perez, 21, of West, was playing basketball at a nearby school when the fire started.
He and his friends thought nothing of it at first, but about a half-hour later, the smoke changed color. The blast threw him, his nephew and others to the ground and showered the area with hot embers, shrapnel and debris.
'The explosion was like nothing I've ever seen before,' Perez said. 'This town is hurt really bad.' There was no immediate official word on what sparked the explosion as emergency personnel assisted victims and doused the flames. U.S. Representative Bill Flores, whose district includes West, said he doubted any foul play was involved.
In a morning press conference, Sergeant Swanton said he had no details on the number of people who work at the plant, which was cited by the Texas Commission on Environmental Quality in 2006 for failing to obtain or to qualify for a permit.
He added that, following the explosion, a 'small amount' of looting was reported overnight.
'There are unidentified people in the neighborhood' around the plant and looters are likely people 'coming in from the street', he said.
Texas Gov. Rick Perry said state officials are waiting for further details about the damage but that he has offered state support.

The force of the blast shattered windows of buildings in the surrounding area - some of the injuries were caused by flying shards of glass

Vigil: Baylor University student's hold a candle light vigil outside Waco Hall for the victim's of the West fertilizer plant explosion

Update: Waco Police spokesperson William Swanton speaks at a media conference on Thursday morning but could only provide limited information

'We are monitoring developments and gathering information as details continue to emerge about this incident,' Perry said in a statement. 'We have also mobilized state resources to help local authorities. Our thoughts and prayers are with the people of West, and the first responders on the scene.'
President Obama also released a statement on Thursday, passing on his condolences and prayers.
'A tight-knit community has been shaken, and good, hard-working people have lost their lives,' he said. 'I want to thank the first responders who worked tirelessly through the night to contain the situation and treat the wounded.
'My Administration, through FEMA and other agencies, is in close contact with our state and local partners on the ground to make sure there are no unmet needs as search and rescue and response operations continue.
'West is a town that many Texans hold near and dear to their hearts, and as residents continue to respond to this tragedy, they will have the support of the American people.'

The disaster even drew condolences from Pope Francis, who wrote on his Twitter account: 'Please join me in praying for the victims of the explosion in Texas and their families.'
In 2001, an explosion at a chemical plant killed 31 people and injured more than 2,000 in Toulouse, France. The blast occurred in a hangar containing 300 tons of ammonium nitrate, which can be used for both fertilizer and explosives.

The explosion came 10 days after the Sept. 11, 2001, terrorist attacks in the U.S., and raised fears at the time it was linked. A 2006 report blamed the blast on negligence.