The first broke out at 20 Pier Street around 8:30 a.m. and quickly spread to a neighboring building.
Officials say the building where the fire started is a vacant two-story house.
The second building, 22 Pier Street, is reportedly an occupied four-story apartment building.
Fire officials say 15 adults and two children were displace by the blaze.
No injuries were reported.
More than 70 firefighters from 16 companies responded to the scene, including mutual aid.