New London — An apartment fire on Riverview Avenue displaced three people Tuesday night.

It was already a busy night for the city's firefighters, who were responding to a suspected heroin overdose and two medical emergencies when the call came in about 9:22 p.m. for a fire at 73 Riverview Ave., Battalion Chief Thomas Curcio said.

A New London police officer was the first to arrive on the scene, evacuating the residents and shutting the door to the third-floor bedroom where the fire was located. Curcio credited the officer's actions with preventing the flames from spreading.

It took the firefighters roughly 10 minutes to knock down the blaze, Curcio said. The third-floor apartment sustained smoke and fire damage, while a first-floor apartment saw water damage from efforts to put out the fire. There were no injuries, and Red Cross was assisting the displaced residents, he said.

The fire marshal's office was investigating the cause of the blaze.