Twelve families were displaced by what officials said was a fast-moving fire that engulfed two multi-family houses in Southbridge early Wednesday morning. The fire was first reported at 3:25 a.m. at 7-9 Union St.

SOUTHBRIDGE — Two apartment houses on Union Street were hit by fire overnight. About 30 residents of the adjacent buildings escaped the flames. There were no reported injuries. The blaze was reported about 3 a.m, with firefighters from several communities responding to the scene.

A Southbridge resident says their home surveillance system captured video of suspicious activity before a blaze broke out and scorched two nearby triple-deckers early Wednesday morning.

Heavy flames and thick smoke roared through two triple-deckers on Union Street in Southbridge early Wednesday morning, threatening to catch a third on fire. “I started knocking on everybody’s door, knocking on the windows,

Union St. and spread to adjacent 11-13 Union St. Southbridge Fire Department Chief Paul Normandin said between 80 to 100 firefighters were on scene. Mutual aid from other communities in Worcester County and Connecticut also helped battle the early-morning blaze.

A raging blaze damaged two triple-deckers in Southbridge early Wednesday morning, forcing dozens of residents from their homes. The fire broke out at a home on Union Street and spread to a second home around 3 a.