Three people missing after a building at a power station collapsed are “highly unlikely” to be alive, the fire service has said.
One person was killed and five others injured when a concrete and steel structure at the derelict Didcot A site in Oxfordshire came down at around 4pm on Tuesday as contractors prepared it for demolition.
Search crews with sniffer dogs worked through the night and into Wednesday in an effort to find the missing.
But speaking at the scene, Dave Etheridge, Oxfordshire Fire and Rescue Service Chief Fire Officer, said: “We have just spoken to the families who are obviously distraught.
“We have explained to them we have not picked up any signs of life but we are doing everything we can to locate their loved ones.
“It is highly unlikely they are alive.”
Mr Etheridge said the operation “may take several days, possibly several weeks”.
Thames Valley Police Assistant Chief Constable Scott Chilton described those in hospital as “seriously injured, but not critical”.
Some 50 people were treated for dust inhalation after the collapse, and a major incident was declared after emergency services were called to the scene.
A 100m cordon has been placed around the site as the rescue operation continues.
Describing the rescue operation, Mr Etheridge said: “We have tried their construction site radios and have had no response. We see this as significant.
“The rescue teams have been working and continue to work through the debris.
“The rescue teams are working under very difficult circumstances with a structure that is unsafe, with unsafe and unstable material from parts of the collapsed building.
“We are currently using sniffer dogs, listening devices, drones, and are looking at the possibility of possibly deploying remote control probes into the structure to access the dangerous parts of the site.”
The facility opened in 1970 as a coal-fired power station and was later converted so it could also generate power from natural gas.
It ceased generation in March 2013 and hundreds gathered to watch when three of its enormous cooling towers were blown up in July 2014.
According to the RWE npower website, the total demolition of the site is expected to be complete by the end of this year.