EAST SPRINGFIELD, Mass. (WWLP) – A mysterious explosion this Saturday morning damaged a garage in East Springfield.

The arson squad called it a minor explosion, but they aren’t exactly sure what caused it.

The garage was attached to a home at 18 Eureka Street. The blast was enough to blow the door off the garage.

Fire Department spokesman Dennis Leger told 22News, there were propane tanks and a Harley Davidson motorcycle in the garage. The bike wasn’t too badly damaged.

The officers suspect the propane tanks may have contributed to the blast, but they’re not exactly sure how.