Lloyd Dale St. Clair, 59, a service adviser at Community Auto Service in Bethesda who received three Purple Hearts during World War II service as a lieutenant in the Marine Corps, died Monday at Prince George's General Hospital after he was struck by an automobile in the 2900 block of Powder Mill Road in Adelphi.

A Prince George's County police spokesman said Mr. St. Clair was crossing the road to catch a ride to work early Monday when he was struck and fatally injured by a car traveling east on Powder Mill Road. Police said the driver of the car was not charged in the incident.

Mr. St. Clair, who had worked for Community Auto Service for the past 26 years, was a native Washingtonian and a graduate of Gonzaga High School. He attended The Citadel military college in South Carolina, Georgetown University and the General Motors Institute.

A private pilot, he worked part-time at College Park Airport and was active in the College Park Civil Air Patrol.

During World War II, he was commissioned in the Marine Corps, and was wounded three times while serving in the South Pacific.

Survivors include his wife, Bonnie Ruth, and a daughter, Bonnie Dale Parker, both of Adelphi; two sons, Gary, R., of Frederick, Md., and Douglas B., of Berkeley, Calif., and two grandsons.