A Calvert County man was killed Monday in a crash with an emergency vehicle responding to a 911 call, authorities said.

Allen Leroy Parker, 75, of Prince Frederick, was ejected from his car when it collided with a medical unit just before 4:30 p.m., on Route 2/4 (Solomons Island Road) at Sixes Road in Prince Frederick, Md.

The emergency vehicle was being driven by 23-year-old paramedic Katie A. L. Kreider, the Calvert County Sheriff’s Office said. Kreider was driving south on Route 2/4, en route to the Lusby area for a 911 call for a heart patient. Officials said her vehicle, a Chevrolet Suburban, was being operated in an emergency capacity with its lights and siren activated.

As Kreider approached the intersection of Route 2/4 and Sixes Road, Parker was attempting to make a left turn from Sixes Road onto northbound Route 2/4. The two vehicles collided at the intersection.

The Suburban hit the left front axle of Parker’s car, a Toyota Camry, then continued across the northbound lanes of Route 2/4 before coming to a stop in a driveway. Parker’s car came to a stop on the southbound grass shoulder of Route 2/4.

Deputies said that Parker, who was not wearing a seatbelt, was thrown from his car and landed in the median of the roadway. Parker did not have a pulse at the scene and was transported to Calvert Memorial Hospital, where he was pronounced dead, officials said.

Kreider sustained serious injuries and was transported to MedStar Trauma.

The collision remains under investigation. Anyone with information or who may have witnessed events leading to the crash can call 410-535-2800 or e-mail bortchvi@co.cal.md.us.