TOPEKA, Kan. (AP) — Authorities are investigating after a car explosion in Soldier Township in Topeka peeled back the roof of a car and sent two people to the hospital. State Fire Marshal's Office investigations chief Rose Rozmiarek says emergency crews and law enforcement responded Sunday morning to an explosion inside a vehicle in the Oakland Expressway bridge. Authorities said a car was traveling southbound when it exploded. The Topeka Capital-Journal reports the driver and passenger, whose identities have not been released, were transported to a Kansas City hospital. Rozmiarek said their conditions are unknown and the cause of the explosion is under investigation.