John Dolph Avery, 39, an emergency medical technician with the D.C. Fire Department, was killed Sunday in a highway accident in the Mount Vernon section of Fairfax County. He lived in Falls Church.

A spokesman for the Fairfax County Police said Mr. Avery was driving alone on Fort Hunt Road near Paul Springs Parkway when his car crossed the center line at a curve and turned over on the opposite shoulder of the road, pinning him underneath. He was pronounced dead at the scene.

Mr. Avery was born into an Army family at Lawton, Okla. He grew up at various military post in the United States and in Germany. From 1960 to 1963, he served in the Marine Corps and was stationed on Okinawa as well as in this country. He moved to the Washington area in 1965 to become a student at the University of Maryland.

While at Maryland, Mr. Avery joined the Branchville Volunteer Fire Department in Prince George's County. From 1966 until his death, he was a member of the Falls Church Volunteer Fire Department.

In 1968, he joined the D.C. Fire Department. He was a firefighter until 1977, when he graduated from the department's first class for paramedics, or emergency medical technicians. He was going to the home of his parents after answering an emergency call when the accident occurred.

Mr. Avery, who was a nationally registered EMT, was a vice president of the Virginia Association of Emergency Medical Technicians and a founder and president of its Northern Virginia chapter. He taught EMT courses at Northern Virginia Community College and was a cardio-pulmonary resuscitation (CPR) instructor with the American Heart Association.

Mr. Avery also was a member of Local No. 36 of the D.C. Fire Fighters Association.

His marriage to the former Patricia Souci ended in divorce.

Survivors include two children, Lee Kathleen and Scott, both of Falls Church; his parents, retired Army Col. and Mrs. James T. Avery Jr., of Alexandria; three brothers, Richard and James T. III, both of Boston, and Robert, of Denver; one sister, Nancy Colligan of Denver, and one grandmother, Mrs. James T. Avery Sr. of Richmond.

The family suggests that expressions of sympathy be in the form of contributions to Heroes Inc., for members of the D.C. Fire Department.