Hopes are fading in the search for three people missing after a deadly collapse at a disused power station.
Emergency crews have now said it is “highly unlikely” they will find anyone alive.
Specialist rescue teams have been using hi-tech detection equipment and sniffer dogs to search through the wreckage at Didcot A power station in Oxfordshire, where a “major incident” occured on Tuesday.
A man is confirmed to have died in the incident and five others were taken to hospital for treatment. Three men have still not been found.
However, rescuers fear the trio did not survive the disaster, which saw thousands of tonnes of concrete and steel reduced to rubble. They say no “signs of life” have been picked up in the wreckage.
Dave Etheridge, chief fire officer at Oxfordshire Fire and Rescue Service, 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.”
He added: “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.”
He said the mission involved working under “very difficult circumstances with a structure that is unsafe”, but sniffer dogs, listening devices, thermal imaging equipment and drones were being used to help locate the missing men.
Remote control probes may be needed to access the most dangerous parts of the site.
“This exercise is going to be prolonged and very difficult.”
Demolition work was under way at the former coal-fired power station, which was turned off in 2013.
Emergency services say the building that collapsed, the former turbine hall, was ten storeys high and 300ft long.
Oxfordshire’s assistant chief fire officer Simon Furlong said search efforts were being hampered by concerns over safety.
“The structure is very, very unstable and we are concerned about the integrity of the building,” he said.