LYNN – Investigators will review video camera footage and check traffic signals to determine how a trash truck crashed into a transit bus Thursday morning on Union Street, injuring two passengers.?We?ll look at the cameras and make a determination on what the causes were,” said Transit Police Lt. Kenneth Berg.The 7:03 a.m. collision sent a 73-year-old Marblehead man to Salem Hospital with what Massachusetts Bay Transportation Authority spokesman Joe Pesaturo described as “a facial injury” and a 46-year-old Boston man was transported to Union Hospital with back pain, said Police Lt. Richard Donnelly.Initial reports indicated three other passengers were treated at the accident scene for minor injuries. Pesaturo said seven people were on the bus when the collision occurred.The Waste Management truck struck the 442 Marblehead bus?s left side midway along the vehicle?s length, sending it slamming into the Lynn Museum?s brick wall. The crash littered the sidewalk with bricks and sent a traffic signal pole crashing to the ground and shattering into pieces.Firefighters and police officers cordoned off the Union Street and Washington Street intersection to pedestrians. The truck sat in the middle of the intersection and the two workers inside the vehicle declined an Item request to discuss the accident.Donnelly said the bus driver told investigators the traffic signal at the intersection was green as the bus traveled down lower Union Street to Central Square. Donnelly said the truck driver told investigators he had a yellow flashing signal as he approached Union Street from Washington Street.?The truck driver will be cited for failing to stop for a red light,” Pesaturo stated in an electronic mail Thursday afternoon.Donnelly said the traffic signal operations will be included in the accident investigation.The museum building is owned by the state, but the museum uses the building for displays and to host events. Director Kate Luchini said no one was in the building at the time of the accident, and displays or historical items were not in the section of the building where the crash occurred.?Luckily, we were between exhibits,” she said.She said the front of the bus “was touching the wall” and split a piece of exterior molding in addition to knocking bricks from the building?s outer wall.The museum is closed this month so that employees can undertake exhibit projects and a second-floor interior lighting project can be completed. Luchini said a scheduled Feb. 3 reopening date will probably be pushed back a week or so in the accident?s wake.?We?re working on a transportation exhibit, ironically,” she said.