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,

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.

SOUTHBRIDGE ― Firefighters fought a raging fire early Wednesday morning on Union Street that displaced up to 35 people. Two three-story apartment buildings with six families each caught fire, according to Fire Chief Paul Normandin.

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.

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.