Fire damage. Photo by Boston Fire Department.

The Boston Fire Department reports nine people were displaced by a one-alarm fire that broke out shortly before 5 a.m. at 130 Devon St.

The department says investigators have determined the fire was deliberately set.

One firefighter suffered a back injury while battling the one-alarm fire, the department reports, adding heavy fire was shooting from rear porches when firefighters arrived. A neighbor suffered a cut foot from broken glass.

The department estimated damage at $200,000.