PITTSFIELD, Mass. — A massive fire in an apartment complex on Saturday afternoon left more than 40 people homeless.

The five-alarm  blaze was brought under control by Pittsfield firefighters after nearly seven hours and with the aid of at least six county fire companies.

No one was injured but the historic three-story Elmwood Court was heavily damaged.

Chief Robert Czerwinski said crews did an initial sweep of the building to ensure no one was inside. All the tenants had gotten out safely; two are out of town.

"We were having a tough time fighting it," said Czerwinski at around 8 p.m. "We're keeping a crew here over night to make sure it doesn't start back up."

The chief said the fire started in the basement and moved through the attic, helped along by the 160-year-old building's balloon construction.

The department received a call of smoke in the basement at about 12:30 Saturday afternoon. As the large fire moved through the 28 apartments, Pittsfield called surrounding towns for mutual aid.

Adams, Cheshire, Lanesborough, Lenox, Hinsdale and Richmond responded. The state's Fire Services Division also responded to provide support and coordination.

Czerwinski said the investigation "will start in earnest in the morning."

The local Red Cross chapter was helping any of the 45 or so tenants in need of aid.

The original mansion was built by Edward Learned, an industrialist and financier, in 1854 and was later known as one of the Berkshire cottages. It housed Miss Hall's School for the first decade of the last century and then was an inn, before being turned into apartments.

The property is owned by Cavalier S.E. Properties LLC, based in Egremont, which purchased it in 2004 from MP Bartlett Realty Trust for $1.1 million.

Updated and rewritten throughout at 9:12 p.m., May 14, 2011.