Investigators are trying to determine the cause of a fire and apparent explosion at a propane supply company on Vashon Island that injured three people. One man was sent to Harborview Medical Center in Seattle with third-degree burns following the fire Friday at Vashon Energy. Two others were taken to Tacoma General Hospital. Vashon Island Fire and Rescue's interim chief Bob Larsen says there were minor explosions and lots of smoke. The blaze had engulfed the building and two cars. It took firefighters about 90 minutes to get the fire under control. Larsen says it was the first time since 2014 that the small fire department called fire crews off the island for help. Investigators are trying to determine if an initial explosion caused a fire or flames caused an explosion.