Raleigh scaffolding collapse: Three workers killed and one seriously injured at high-rise building in North Carolina

The tragic incident occurred at around 11am on Monday morning

A section of scaffolding protrudes from a shattered window at the scene of a construction accident that killed three people and sent another to a hospital, Monday, March 23, 2015, in Raleigh, N.C. A scaffolding holding at least three workers fell and cra (AP Photo/The News & Observer, Harry Lynch)

A collapsed scaffold on a high-rise building in North Carolina has killed three workers and hospitalised one other.

The workers were attempting to remove and lower scaffolding on the 11-storey Charter Square building in downtown Raleigh this morning, when a problem occurred shortly after 11am, Mike Hampton, the chief operation officer of the project’s contractor, told the WRAL local television station.

Witnesses on the scene said they heard what sounded like an explosion and saw scaffolding crash into the building’s south side between the fifth and sixth floors.

None of the workers involved have been identified, and it remains unclear if they were standing on the scaffold, or tethered to an object.

Other workers at the scene said the hospitalised man suffered serious injuries after he was discovered breathing but almost unresponsive in a portable toilet. It is not clear whether he was inside the toilet or fell from above, according to BBC News.

Wake County EMS district chief Jeffrey Hammerstein told BBC News that the four workers were all involved in the construction project.

Police, the North Carolina Department of Labor and the Occupational Safety and Health Division were investigating the incident.

Speaking on behalf of the Raleigh City Council, Mayor Nancy McFarlane expressed her condolences for those involved in the incident.

“I was incredibly saddened to learn of the construction accident that occurred this morning at the Charter Square construction site,” McFarlane said.

“I would like to offer our sincere condolences to the families and friends of the workers who tragically lost their lives. Please keep the workers and their families in your thoughts and prayers during this very difficult time.”