One person was found dead in the wake of a deadly three-alarm fire that ripped through a Cambridge apartment building early Tuesday morning, the Cambridge Police Department reported.

The fire was first called in at the Chester Street apartment building at about 4:40 a.m., the department said in a release. Multiple witnesses at the site reported a loud explosion quickly followed by a heavy volume of fire, according to a city spokesperson.

Responding units initially found a sizable blaze at the four-story building, the department said, which rose to three alarms.

Many residents were reportedly alerted by their smoke alarms and escaped quickly, and one was rescued one occupant trapped through a third-floor window using an aerial ladder, Cambridge Police said.

The fire was brought under control by 5:15 a.m., the department said. Firefighters contained the blaze to the second-floor apartment at the front left of the building, before entering to “conduct an aggressive interior attack.”

In the apartment, responders found a deceased adult man, the sole occupant of the unit, according to the department.

The man has not been identified. The medical examiner will conduct a formal identification procedure and determine the cause and manner of his death.

Fifteen other residents were displaced by the fire, though authorities believe “much of the building” will be habitable after cleanup, the department said in the release. Located near Davis Square and Porter Square along the Red Line, the building reported contains 30 studio and one-bedroom apartment units. Red Cross and the Salvation Army are actively assisting residents.

One firefighter was transported to the hospital with “not life-threatening” injuries, the department said.

The cause of the fire remains under investigation by Cambridge Fire, along with state and local police. The Department of Fire Services’ Code Compliance and Enforcement Unit, Somerville Fire Department, and the Boston Sparks Association A-10 assisted on the scene.