The Associated Press

BALTIMORE — A sport utility vehicle and a fire truck collided early Sunday, killing the three occupants of the SUV and injuring four firefighters, the fire department official said.

The fire truck crew was responding to a report of smoke in a building, said department spokesman Kevin Cartwright.

The department was conducting a routine internal investigation and it wasn't yet clear yet if rain or wet conditions in the area contributed to the crash, he said.

The police department also was investigating, said Sterling Clifford, a spokesman for the police department and the mayor.

The three occupants of the SUV, two men and a woman, had to be cut out of the wreckage, Cartwright said.

Two firefighters, an officer and an emergency vehicle driver were treated and released, Cartwright said.

The fire department did not immediately give any details on the smoke report that the fire truck crew had been sent to investigate.