18 April 2013 Last updated at 18:03
Texas Waco fertiliser plant blast search for survivors
Emergency services are searching for survivors after a blast at a fertiliser plant in the US state of Texas killed between five and 15 people.
More than 160 people were injured and dozens of buildings destroyed in the town of West, near Waco.
Three or four volunteer firefighters are among the missing after the explosion, which produced a tremor equivalent to a small earthquake.
Emergency services officials said ammonia may have caused the explosion.
There is no indication that the blast and a fire which preceded it were anything other than industrial accidents, police say.
However, the site is being treated as a crime scene and the death toll could rise, officials warn.
Texas state Governor Rick Perry said he was declaring the area a disaster and would request an emergency declaration for federal aid from US President Barack Obama.
He said President Obama had agreed to fast-track a declaration.
Air quality and gas pipelines were being monitored for safety, he said. and gas supplies had been disconnected until any risk had passed.
Footage shows casualties, some in buses, piling into a nearby hospital, as the BBC’s Nick Childs reports
The operation is still in “search-and-rescue mode” and has not yet moved to “recovery mode”, Waco police Sgt William Patrick Swanton told a news briefing on Thursday morning, some 12 hours after the explosion at 01:00 GMT (20:00 local time).
Between five and 15 people were killed, he said.
The explosion devastated the West Fertilizer Company, about 20 miles north of Waco, in central Texas.
The plant contained tanks of volatile anhydrous ammonia, including what initial reports said was a tanker-sized container like those hauled on freight trains, Sgt Swanton said.
In 2006, the plant was cited by the Texas Commission on Environmental Quality for failing to obtain or to qualify for a permit.
Dozens of homes were levelled and other buildings – including a school and nursing home a few hundred metres from the plant – were badly damaged.
Jason Shelton, 33, who lives less than a mile (1.6 km) from the plant, told the Reuters news agency he felt the concussion from the blast as he stood on his front porch.
“My windows started rattling and my kids screaming,” Mr Shelton said. “The screen door hit me in the forehead… and all the screens blew off my windows.”
More than 130 people had already been evacuated from the nursing home by the time of the explosion because the fire was recognised as a risk.
It was not immediately clear how many of them were hurt, a public safety department spokesman told a news conference.
A husband and wife who entered the nursing home before the emergency services arrived found residents in wheelchairs trapped in their rooms, the Associated Press (AP) reported.
“They had Sheetrock [plasterboard] that was on top of them. You had to remove that,” William Burch told AP. He described hallways filled with water and electrical wires hanging from the ceilings.
US President Barack Obama said his administration was in close contact with emergency services at the scene.
“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,” he said in a statement.