A young woman was fighting for her life after an explosion tore apart a block of flats.
Sarah Pearse, 19, was one of twelve people injured in the blast in Shrewsbury, Shropshire, on Sunday.
She was taken to Selly Oak Hospital in Birmingham where a hospital spokesman described her condition as "extremely critical".
Two other people seriously injured in the explosion, a man and woman, were said to be in a "critical but stable" condition at the hospital.
The blast is believed to have been caused by a gas leak. Police and Health and Safety Executive contractors were at the scene, on the corner of Bridge Street and Smithfield Road, near Welsh Bridge, working to pinpoint the source.
Superintendent Martin Whitelegg, from West Mercia Police, said: "There is no evidence that this was a criminal incident, we are not treating it as a crime at this current time.
"It is being treated as a probable gas leak... it is believed the explosion was caused by an escape of gas in the vicinity, either in the street or in the building."
One woman inside the flats was flung from a room in the first floor of the building onto the street outside, such was the ferocity of the explosion. Another man was trapped on the ground floor and five people in a car outside had to be dragged free by bystanders after the vehicle was struck by falling rubble.
A police spokesman said on-site investigations would continue for "several days, if not a week".
A number of witnesses have told officers they could smell gas in the area close to the flats before the explosion at 11.30am and a nearby gas main has been isolated, the police spokesman added. Roads close to the scene remained cordoned-off this afternoon and the streets adjacent to the flats were still covered with shattered glass, blown out by the blast.
