Two persons were killed and a third was injured yesterday after a car crossed the center line of a road in western Loudoun County and hit a second car head-on, Virginia state police reported.

The collision occurred about 4:40 p.m. when a car driven by Larry Edgar Grimm, 39, of Sharpsburg, Md., crossed the center line of Rte. 671 a mile south of Rte. 340 and hit a car driven by Ora B. Cassidy, 69, of Purcellville, Va., police said.

Cassidy and his wife, Mabel, also 69, were returning from a Christmas shopping expedition and were only 120 feet from the driveway of their home, state Trooper A.D. Blankenship said.

Grimm was pronounced dead at the scene, Blankenship said, while Ora Cassidy was flown in a Maryland state police helicopter to Washington County Hospital in Hagerstown, Md., where he was pronounced dead at 7:20 p.m.

Mabel Cassidy was reported in satisfactory condition at Loudoun Memorial Hospital in Leesburg with a broken hip.

Blankenship said witnesses who had been driving behind Grimm's car told police that the vehicle had appeared to be driven erratically. The trooper said that alcohol was found in Grimm's car and that the investigation of the accident is continuing.

None of the occupants of the two cars was wearing a seat belt, he said.