Four people have been taken to hospital and three are still missing following the Didcot Power Station collapse which left one person dead.
Energy company npower said part of the Boiler House at the former power plant in Oxfordshire collapsed after 4pm yesterday “while an external demolition contractor was working in it”.
A statement from Oxford University Hospitals NHS Foundation Trust stated: “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.”
Emergency services said it was a partial collapse of a large building, around 300m long and 10 storeys high.
More than 40 people were treated at the scene for dust inhalation and have since been discharged.
The Oxfordshire Fire and Rescue Service said it is looking for the three missing people with sniffer dogs and search equipment, including two drones.
However it added the building is “very unsafe which is hampering search”.
Simon Furlong, Assistant Chief Fire Officer said: “This is a very difficult situation with a very unstable structure.
“The safety of emergency service personnel has to remain our priority while recognising how hard this must be for families waiting for news of loved ones overnight. Our sympathies are with them and the family of the person who died here yesterday.”
The Health and Safety Executive added it has launched an investigation to find out what happened.
In a statement on Twitter yesterday, contractors Coleman and Company said it is “working with all stakeholders to establish facts”.
Energy firm npower added: “Our thoughts are with the families of all those involved in this tragedy. We will provide updates as we receive them.
“We are working with the emergency services who are currently on site to understand the cause of this collapse.”
Didcot A is a dual-fired power station, which began commercial operation in 1970 and closed in March 2013. It was due to be demolished by the end of the year.