New York City subway riders were shocked when part of a station's ceiling collapsed onto the platform shortly before the start of rush hour.

Straphangers awaiting the 4 and 5 trains on the Manhattan-bound platform at Brooklyn's Borough Hall subway station reported hearing a 'loud bang' and then seeing hunks of concrete, bricks and other debris striking the platform floor.

The collapse occurred at about 3.30pm Wednesday.

Straphangers at the Brooklyn Borough Hall station were surprised when part of the station's ceiling collapsed Wednesday at 3.30pm, shortly before the start of rush hour

Brooklynite Eric Chan was standing on the opposite platform from where the ceiling collapsed and tweeted that he heard a loud bang before seeing the ceiling detritus on the platform

Pictures showed a chunks of concrete, bricks and other debris, as well as a dangling light strip

A view of the area where the subway ceiling partially collapsed onto the platform below

A patch of bare brick was revealed in the area where the crumbling subway ceiling collapsed

In a tweet directed at the New York City Subway's Twitter handle, Brooklynite Eric Chan wrote, 'I heard a loud bang, I turn around, and a part of the ceiling COLLAPSED. This was on the Manhattan bound 4/5 train platform near the front end.

'There was a lady standing close to the platform edge and her suitcase got knocked over from the debris, I hope she’s okay,' Chan wrote, accompanying the tweet with a picture of the platform covered in building detritus and a lighting fixture hanging askew.

Other pictures posted on Twitter show the debris from different angles, as well as first responders arriving on the scene.

The FDNY said a 50-year-old man received a minor injury as a result of the ceiling collapse, NBC News reported.

CBS News reported that the man was struck on the shoulder and refused medical treatment at the scene.

Manhattan-bound train service on the 4 and 5 lines will be bypassing the Borough Hall station and the MTA said riders should expect delays in all trains that pass through that station.

The FDNY reported that a 50-year-old man sustained a minor injury during the incident