Boston firefighters responded at 4 a.m. to 8 Marie St., near Ronan Park, for what turned into a six-alarm fire that damaged four three-deckers on Marie and Fox streets, causing an estimated $2.5 million in damage.

No residents were hurt; one firefighter suffered an ankle injury, the Boston Fire Department reports.

Some 17 people were displaced by the fire, which started in the vacant 8 Marie St. and spread to 6 and 10 Marie. A three decker on Fox Street, some 70 feet away, also suffered damage.

The cause and origin of the fire are under investigation.