Three Boston firefighters were injured Friday when a five-alarm blaze tore through a triple-decker home on Clover Street, displacing 16 residents, Fire Commissioner Joseph Finn said.

The firefighters, two with arm injuries and one suffering heat exhaustion, were taken by ambulance to a hospital for treatment, said Boston Fire Commissioner Joseph Finn.

Their conditions were not known, Finn said at the scene.

The department received numerous calls reporting the fire at about 4:50 p.m. The flames were visible from several area vantage points, Finn said.

He described a “stubborn fire’’ that tore through the rear and attic of the home at 9-11 Clover St. Damages were estimated at $1 million, Finn said.

As they fought the blaze, fire crews were visible through large holes in the roof caused by the fire. “It was a very significant fire for us,’’ Finn said.

Finn said he did not know if anyone was home at the time of the fire. Investigators are working to determine the cause, he said.

Residents were being assisted by the Red Cross and wouldn’t be allowed to return to their homes Friday night, he said.

Richard Daley, who lives across the street, said 10-foot flames were shooting through the roof when firefighters arrived.

As he stood outside, trying to shoot a video, blowing embers burned two holes in the Patriots sweat shirt he was wearing. He was concerned about the blaze until firefighters arrived.

“These guys showed up, and I knew we were all set,’’ Daley said.

Anne Fancelli, a neighbor, said she saw firefighters battling through “lots of smoke and flames.’’

“Those firefighters were working hard,’’ she said.

Another neighbor, Pat Dennehy, offered her own high praise.

“Bless these firefighters,’’ she said.

John Hilliard can be reached at john.hilliard@globe.com. Follow him on Twitter @Draillih.