Fairfax County police officer Karen Jean Bassford, became the first County police officer to die in the line of duty early yesterday when the cruiser she was driving skidded out of control, split a utility pole and then crashed into a tree.

Police reported that Bassford, who was assigned to the McLean substation, was responding to a reported burglary in progress in McLean when the accident occured. The burglary report was unfounded, they said.

Bassford was traveling at a high speed and had her squad car's flashing red lights turned on when she rounded a curve on Galloms Road at Merry Oaks Lane near Vienna. She lost control of the vehicle, police said, and it slid 477 feet before running off the right side of the road and hitting the utility pole. Bassford's body was found 15 feet from the cruiser, police said.

Bassford was alone in the cruiser and there apparently were no witnesses to the accident, police said. She was pronounced dead on arrival at Fairfax Hospital at 12.35 a.m.

Bassford, who was sworn in as a Fairfax police Officer in June, 1976 was the first officer killed in the line of duty in the 37-year history of the department, police said.

Fairfax County police Lt. John Isom. Bassford's supervisor, said, "She was...a very good police officer. It's quite a shock, especially since she came out with top honors at the Northern Virginia Police Academy in pursuit driving."

Desk officer Joseph Parr described Bassford, who was one of three female officers at the 75-officer Mclean substation as "a very aggressive person for being a woman in police work." Parr said, "While she was not in stature as big as the men, she wasn't afraid to take charge of situations. She did very well and was just like the other troops."

Arlington County Chief Deputy Sheriff C.N. Gray. Bassford's former supervisor said "She was a very likable, very intelligent, very attractive person and had all the qualifications of a police officer. I recommended her for the job at the Fairfax Police Department. She was a very good person and one of our best (deputies)."

Born in Arlington. Bassford grew up in Fairfax County and was a 1965 graduate of George C. Marshall High School in Falls Church. From 1969 to 1974 she was a communications clerk with the Arlington County Police Department. She served as a deputy sheriff in Arlington from February, 1974, until June, 1976.

Bassford lived with her parents, Mr. and Mrs. George Bassford, and her brother, George Jr., at 6630 Hallwood Ave., Falls Church.