A firefighter has been shot dead and his colleague wounded while responding to an emergency call out in the US.
The pair were responding to a medical call out when the incident happened in Temple Hills in Prince George's County, Maryland, CNN reported.
The man who died was John Ulmschneider, 39, who had been a firefighter for 13 years and was also a trained paramedic.
His colleague, volunteer firefighter Kevin Swain, was also shot and critically injured.
The person who called 911 was also shot and wounded.
County police chief Henry Stawinski gave details of the incident at a press conference.
He said the shot men were called to the address by a concerned relative about a man who lived there.
"When there was no answer, entry was forced. The person inside the home fired shots that struck a firefighter from the ambulance, a firefighter from the engine company and the relative who originally who called for help.
Fox News reported that Mr Ulmschneider was shot in the chest and transported to MedStar Southern Maryland Hospital Center where he later died.
Prince George's County Fire and EMS spokesperson Mark Brady said Mr Swain was shot multiple times. He was airlifted to the University of Maryland Shock Trauma Center in Baltimore and underwent emergency surgery. He remained in a serious condition.
Prince George's County Executive Rushern Baker described the firefighters as brave.
"These men and women put their lives on the line, and unfortunately tonight, we lost one of them ... This is a sad day in Prince George's County."
The alleged shooter is in police custody.
No shots were fired at the alleged offender. He is said to be cooperating with police.
Charges were yet to be laid.