Three businesses inside a building in Oregon City were damaged Wednesday morning after a big fire.  Crews called 3-alarms so they could get more help battling the flames.  An explosion caused a back draft, which burned one firefighter.  His injuries are described as minor.  Crews also had to dodge power lines, as the flames burned through the live wires, causing them to fall to the ground.

An investigator is combing through the building at 1015 Molalla Avenue, trying to figure out what started this blaze.