EMERGENCY rescue teams were today searching for three people feared dead in a collapse at the former Didcot power station.
One person was killed and five others were injured when a huge section of the old turbine hall gave way.
Witnesses described seeing a massive grey-brown cloud as the collapse happened and dust covered a large area.
About 50 people were treated for dust inhalation on site after the emergency services rushed to the scene.
The incident happened at the former coal-fired Didcot A plant, which closed in 2013 and is in the process of being demolished, at about 4pm yesterday.
All the missing and injured workers are employed by demolition contractor the Coleman Group.
Five were taken to the John Radcliffe Hospital in Oxford, one with serious injuries.
Police, six ambulances and two air ambulances were sent to the scene.
About 60 firefighters together with specialist rescue teams, including sniffer dogs, were involved in searching through a rubble pile up to 30ft deep.
A 300ft cordon was put in place and at one point a no-fly zone was imposed so the teams had silence to listen for any human cries.
An official from the GMB union said the collapse of the 10-storey building may have been triggered by work on two boilers.
“We understand that workers were preparing two boilers for demolition in the coming weeks,” it said. “This led to the collapse.”
Colin King, 44, who lives near the power station, said: “There was no bang, just a loud rumble.
“Normally we get given information on anything big they’re doing. We usually hear small bangs but I knew something was out of the ordinary.
“Once I heard all the sirens I knew it was serious. Then I saw half the building hanging off.”
Nathan Travis, deputy chief fire officer for Oxfordshire, said: “The building is potentially 10 storeys high — half of that building has collapsed.
“So you have got a rubble pile which is approximately 20 to 30 feet deep at the moment. The search will be considerable due to the instability of the site.
“We expect the search to continue.... possibly into the coming days. It is a substantial collapse of a building.”
Chief fire officer Dave Etheridge described the collapse as a “very severe incident” and expressed his “deep thoughts to all the families involved”.
He added: “We are doing our very best to secure the return of their loved ones as soon as we can.”
A spokesman for the hospital said: “Four of the men are in a stable and non-life threatening condition, while one man is in a serious but not life-threatening condition.”
Didcot A 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 its cooling towers were blown up in July 2014 after dominating the skyline for more than four decades.
According to the RWE Npower, which owns the plant, total demolition of the site was expected to be completed by the end of this year.
Yesterday’s incident comes 16 months after a major fire in a cooling tower at Didcot B. The blaze affected 50 per cent of the station output, which supplied a million homes.
An Npower spokesman said: “Our thoughts are with the families of all those involved in this tragedy.”