PITTSFIELD, Mass. — An early morning fire on Lincoln Street heavily damaged a duplex and injured four, including three firefighters.

One occupant of the home was taken by ambulance to Berkshire Medical Center for treatment of burns and smoke-related injuries. Two pets are also missing and another, a cat, died in the blaze.

Two firefighters suffered minor lacerations and another smoke inhalation; all three were treated at the scene.

The cause is under investigation by the Fire Investigation Unit, state fire marshal's office and the Police Detective Bureay.

City firefighters responded to the 2-alarm blaze with five engines and the ladder truck to the structure fire at about 4:13 a.m. According Deputy Chief Michael Polidoro, there was heavy fire extending to the second floor when fire units arrived on the scene.

It took 90 minutes to bring the fire under control. There is heavy fire damage in the front on both the first and second floors and smoke and heat damage to the rest of the building. The owner of the building lived on the first floor; a tenant on the second.

All of the occupants were displaced and the Red Cross was contacted to assist them.

Western Massachusetts Electric Co., Berkshire Gas and city inspectors assisted at the scene; Dalton Fire Department covered the city.