A man was killed and a dozen people were injured in a chain-reaction crash involving an FDNY firetruck in Brooklyn on Tuesday night, city officials said.

According to the NYPD, the chaotic collision happened around 6:45 p.m., when a firetruck with its lights and sirens on collided with a Ford Transit van at the intersection of Avenue S and West 11th Street in Gravesend.

The impact sent the firetruck — which was heading eastbound on Avenue S — into the westbound lane, where it slammed into an Access-A-Ride coach bus, police said. The coach bus then hit a Lexus SUV, and the firetruck hit two unoccupied parked cars before coming to a stop, according to officials.

Emergency medical workers took six firefighters to a local hospital, along with the 45-year-old man driving the van, the 31-year-old man driving the Access-A-Ride bus, three passengers, the 71-year-old man driving the Lexus, and his passenger, authorities said.

Police said a 78-year-old man, one of the Access-A-Ride passengers, was taken to South Brooklyn Health in critical condition and later died. Officials identified him early Wednesday as Placido Dandrea and said he lived down the block from the crash site.

All the others involved in the crash were reported in stable condition.

The NYPD said it is still investigating the incident and could not yet say which vehicle had the right of way.

The FDNY did not immediately provide details on where the firetruck was going at the time of the crash.

The MTA, which oversees Access-A-Ride paratransit services, referred to the two other agencies for comment.

This story is based on preliminary information from city officials and may be updated.