Navy blames sub fire on heat source in vacuum

KITTERY, Maine (AP) -- The Navy says a fire that caused hundreds of millions of dollars in damage to a dry-docked submarine started when an industrial vacuum cleaner sucked up a heat source of some type that ignited debris inside the vacuum.

The Portsmouth Naval Shipyard issued a statement Friday that the vacuum had no apparent defect and was not plugged in when the fire started aboard the USS Miami on May 23. The Navy estimates the repair cost at $400 million.

The shipyard says that an investigation is ongoing and that additional details and a final damage assessment will be released later.

Officials said all public shipyards have been directed to empty their industrial vacuum cleaners after each shift or remove them from ships.