Portage, IN – An unbalanced washing machine load likely caused the explosion that knocked a Portage house off its foundation Wednesday.

Portage Fire Department investigators noticed that the washing machine in the basement had been in direct contact with a gas-line valve. The quarter-turn valve was in the on position and there was no cap on the line.

A large load of laundry was in the washer and it had stopped before it was complete.

Renter Patrice Wilburn told firefighters that she was doing laundry before leaving for work Wednesday morning.

Firefighters determined the gas line was opened by an unbalanced load in the washer. It was moving back and forth and caused the quarter-turn valve to open, filling the basement with natural gas. When the water heater turned on, the gas ignited, causing an explosion. Firefighters confined the fire to the basement and quickly extinguished the blaze.

Investigators ruled that the fire was accidental.

Assistant Fire Chief Joe Calhoun said this situation is rare but not uncommon.

“When you move appliances around, it’s a good idea to do routine maintenance and test for leaks with soapy water,” Calhoun said.

The force of explosion knocked out most of the windows in the house and separated the walls from the foundation.

Assistant Fire Chief Mike Bucy said the house is uninhabitable and a total loss. Its value is estimated at $140,000.