Fort Madison, IA- The Fort Madison Fire Department says that a Saturday garage fire was caused by an acetylene tank explosion. The Pen City Current reports that at about 8:30 PM Saturday, reports came in to LeeComm of an explosion in the 1100 block of Avenue E. Fort Madison Fire Chief Joey Herron said that the fire started when an acetylene tank exploded inside of a garage, causing multiple other tanks to explode and destroying the garage. The fire is under investigation and the cause of the explosion is unknown. No injuries were reported.