Lakewood police are investigating after a small camper explosion and fire that sent three people to the hospital Wednesday night. It happened just before 8:30 p.m. on Fern Street Southwest, near American Lake. Officials said a woman and two men were inside the detached camper when it exploded. All three suffered burns and were taken to Harborview Medical Center for treatment. All three were listed in stable condition. Firefighters said the explosion may have been caused by a some sort of problem with lighting the propane stove inside the camper.