Four people, including a city police officer, were seriously injured last night when a patrol car on an emergency call collided with a Cadillac at an East Baltimore intersection.

Police said Officer Heidi Hebron was eastbound on East Fayette Street, responding to a "Signal 13" for an officer needing help about 10 p.m. when her car - with siren and emergency lights on - struck the passenger side of the other car, which was southbound on Broadway and occupied by three men.

Both vehicles were destroyed, and the officer and at least two of the men were briefly trapped in the wreckage. All four were taken to nearby Johns Hopkins Hospital's trauma unit.

The officer's injuries were described by police as not life threatening, but her condition and those of the men were not immediately known.