We may never know the cause of a house explosion in St. Joseph County.

Last September, a home in the Arbor Point subdivision exploded, killing the homeowner, 66-year-old John Floyd.

Several other homes were also damaged.

The Clay Fire Territory says a build-up of natural gas led to the explosion, but investigators do not know what caused that build-up.

They say evidence taken from the home was too badly damaged.

John Floyd was a Washington High School security guard and former South Bend police officer.