On Wednesday, two people were sent to the hospital with severe burns after an explosion at a Chattaroy Mobile Home Park. Neighbors say they heard a large explosion in a single wide mobile home in the Chattaroy Valley Estates followed by a large column of fire and black smoke. An off duty firefighter told KHQ he heard the explosion and immediately responded while calling for help. Emergency crews on scene found a home comes lately engulfed in fire and discovered two people who were inside badly burned and being helped by neighbors. The man and woman who were inside at the time of the explosion were both taken to Sacred Heart Medical Center in Spokane before re-routed to Harborview Medical Center in Seattle with severe burns all over their bodies. Detectives from Spokane County's Major Crimes Unit, along with investigators from Spokane County Fire District Four are looking into what caused the explosion. Because they can not say for sure it was an accident, they are treating the area as a crime scene. Investigators will remain on scene through early Thursday morning and detectives will be back in the morning with a search warrant for what's left of the home.