Firefighter killed in Leonardtown house fire

BALTIMORE -- A firefighter died in a Leonardtown house fire Tuesday morning, officials said. 

The firefighter has not been identified, but officials said the man was part of Patuxent River Naval Air Station. Another volunteer firefighter was injured at the scene, but his condition is unknown. 

Units responded to the scene around 4 a.m. at the 20500 block of Deer Wood Park Drive in St. Mary's County. Aerial images of the scene show the home heavily damaged by the blaze. 

The Naval Air Station was providing mutual aid to other engines already on the scene, Navy Capt. Derrick Kingsley said. 

We're grieving a loss right now, thoughts and prayers to family and to the larger Navy team," Kingsley said. "We lost a true hero this morning that went in without hesitation to save others, and lost his own life in the process."

No further injuries were reported. It was not immediately clear how each firefighter was injured. 

The St. Mary's County Sheriff's Office said travelers should expect delays in the area of Point Lookout Road and Redgate. 

The firefighter will be identified after 24 hours pending next of kin notification, officials said. 

The cause of the fire remains under investigation. The fire marshal's office said 15 investigators, which it said is a quarter of its personnel, are investigating the cause with other local agencies. 

"This will be an extended operation, and every resource of our agency, along with our partners, will be used to provide answers," the agency said in a tweet. 

This is a developing story and will be updated.