One person is dead and three others are missing after a building collapsed at Didcot power station in Oxfordshire, England, fire officials say.

"There has been an incident at our former Didcot A power station site in Oxfordshire. The site is currently being demolished. We are working with our contractors Coleman and Company to establish the facts and will keep you updated as soon as we have more information," N Power, which owns the site, said in a statement. 

The collapse occurred around 4 p.m. local time, and it's been rumored that it was caused by workers preparing two boilers for demolition. Similar sources say there was a bang at the site, but officials say they're treating the sound as the aftermath of the collapse rather than the cause. 

"At the moment this is being treated as a collapsed building, not an explosion, but there was a bang," Oxfordshire County Council Deputy Leader Rodney Rose said, according to the BBC.

Five fire engines along with support vehicles including Specialist Resuce and Command Support Units, and Urban Search and Rescue Units from Buckinghamshire, quickly arrived at the scene. Once there, they were able to rescue five people and confirm one death.

Responders are now in the midst of a search for three people who remain unaccounted for.

"At this time the cause is unknown and the search is continuing for three missing people, with five in hospital and one fatality confirmed," Chief Fire Officer of the Oxfordshire Fire and Rescue Service Dave Etheridge said, according to the Guardian.

It's been noted that the building was slated for demolition in 10 days, and an investigation will be launched once the status of the missing three workers is verified.