Second-half rallies by the Washington basketball teams fell short today at the 13th annual U.S. Youth Games at the University of Richmond.

The boys' squad ended up on the short end of a close score, losing to Richmond, 58-55, in the losers' bracket final and bowing out of the double elimination tournament with a 3-2 record and the bronze medal.

The Washington girls turned back East Orange, N.J., 58-52, to survive the losers' bracket final this morning. In the afternoon championship, however, undefeated Boston held off the D.C. girls, 63-51, to claim the gold medal. The Washington girls earned the silver medal with a 4-2 mark.

Adrian Branch scored 20 points and Kelvin Johnson 19 as the D.C. team rallied from a 35-19 halftime deficit to close within six as the third quarter ended. A shot by Branch with 3:30 to play pulled Washington within two, and Daryll Webster's free throw cut the margin to one with seven seconds left.

Richmond's James Williams, the game's high scorer with 25 points, was fouled on a rebound attempt and sank two free throws to produce the final edge.

Richmond fell to Worcester, 61-48, in the afternoon championship.

The Washington girls avenged an earlier loss to East Orange with their triumph this morning. Britt Kind had six rebounds and Jacquelen McKinnon dropped in 24 points.

Jeannette Kelly highlighted the track and field competition for Washington as she broke her 1978 Youth Games record to win the girls' 15-under 880 in 2:1.7. The D.C. girls finished second to New York (166 to 97 1/2) in the team standings; the Washington boys finished fourth.

Norman Fisher won the 15-under girls' 220 in 24.5 seconds. Darren Smith won the boys' 11-under 220 in a judges' decision, beating New York's Steven Brown.

The Washington girls' 880 relay team was first in the 15-under event in 1:44.8 and the 13-under girls took second in the 440 relay, 1.1 seconds behind New York.

Derrick Holmesley won the boys' 11-under long jump at 16-7, 1 1/2 inches ahead of Detroit's David Artist.

A fourth-place finish in the boys' 13-under 200 individual medley by Mark Van Ryne was Washington's top performance today in swimming. Jeanmarie Brown was fifth in the 14-15 girls' 50-yard freestyle.