Seven Injured in Nuclear Submarine Fire [VIDEO]

KITTERY, Maine – Seven people were injured in a fire on a nuclear submarine at the Portsmouth Naval Shipyard on Wednesday night.

The fire occurred in a forward compartment of the USS Miami SSN 755 that is primarily used for living areas and command and control spaces. The ship's reactor was not operating at the time and was reportedly not affected. Navy officials say it's too soon to tell if the $900 million submarine will be salvageable.

The cause of the fire remains unknown. An investigation into the cause has been launched, but is expected to take a long time to complete. Officials aren't saying if human error has been ruled out or if the focus is on mechanical issues.

The fire was reported at 5:41 p.m. Wednesday, , according to the shipyard. The nuclear propulsion spaces were physically isolated early in the event from the forward compartment fire and remained safe and stable throughout the event.

Capt. Bryant Fuller, the shipyard's commander, said there were no weapons on board, and all personnel were accounted for.

Seven people were injured in the blaze, according to the shipyard, including three shipyard firefighters, two ship's force crew members, and two civilian firefighters providing support. All seven were treated and released and were said to be doing well. Their names are not being released.

Firefighters from numerous Seacoast communities, including Portsmouth, Kittery, York, South Berwick, Somersworth, Rollinsford, Rye and New Castle, provided mutual aid. An engine and foam truck were requested from Logan Airport in Boston. State, local and federal authorities were also notified.

The shipyard gates remained open throughout the ordeal, and the workforce is expected to report to work as scheduled.

According to the shipyard's website, the USS Miami arrived here on March 1 for maintenance work and system upgrades. It has a crew of 13 officers and 120 enlisted personnel. The website says the Miami is the third Navy ship named for the city of Miami and the fifth "Improved" Los Angeles-class nuclear-powered submarine. Assigned to the Atlantic Fleet, the Miami was commissioned on June 30, 1990, and its home port is Groton, Conn.