Image copyright CBS

Three workers are dead and one other is in hospital after a section of scaffolding has collapsed at a tall construction project in North Carolina.

Emergency responders say the platform peeled away from the glass and steel building and collapsed into a car park in Raleigh.

Authorities are working to identify the dead and the cause of the accident.

Construction industry accidents are the leading cause of workplace death in North Carolina, officials say.

The four workers were all involved in the construction project, Wake County EMS district chief Jeffrey Hammerstein said.

Other workers at the scene said the surviving worker, who is reported to be severely injured, was found breathing but almost unresponsive in a portable toilet.

It is not clear whether the man fell into the toilet or was inside when the scaffolding fell.

The workers were removing and lowering the scaffolding when the collapse happened around 11:00 local time (15:00 GMT), local television station WRAL reported.

Image copyright CBS Image caption Rescue workers stand near what appears to be the collapsed scaffolding

Emergency officials have cordoned off the area around the construction site, and state and federal investigators are said to be on the scene, according to WTVD, another local television station.

The 11-story building under construction is set to open in May, local reports say.

Nineteen people were killed at construction sites in North Carolina in 2014, according to the state's labour department.