Two people were displaced after a heavy fire broke out at a house in the Mattapan neighborhood of Boston late Friday night. The Boston Fire Department responded to the Hannon Street fire at about 11:15 p.m. There were no reported injuries, according to the fire department, and they said the exact cause of the fire remains under investigation. Detail companies remained on the scene to monitor any hot spots, after the heavy fire was knocked down and firefighters vented smoke.