A 12-year-old Georgetown Day School student was fatally injured early yesterday on Canal Road NW when he was struck by a van as he and four friends were returning from a movie, D.C. police said yesterday.

The boy, Tor Rostad, 2723 P St. NW, was pronounced dead on arrival at D.C. General hospital about 5 a.m. yesterday according to police in the traffic division. Police said Rostad had massive head injuries.

The driver of the 1977 Dodge Van that struck and killed Rostad, Bernoit Maubrey, 26, was charged yesterday with manslaughter and driving while under the influence of alcohol, police said. Maubrey apparently lives in New York but this weekend was visiting his mother, who lives at 4402 Volta PL NW, police said.

Police said that after running off the road and striking Rostad, the van hit a utility pole and turned over. Maubrey suffered a fractured kneecap in the accident. He was listed in satisfactory condition yesterday in the special prison lockup ward at D.C. General Hospital.

According to police, friends of Rostad and the families of the youths who were with Rostad when he was killed, the boys were returning from the midnight showing of "The Rocky Horror Show," a movie playing at the Key Theatre in Georgetown about 3:45 a.m. They were headed westward on Canal Road as it merges with Foxhall Road and MacArthur Boulevard street - toward the Volta Place NW home of one of the youths, Ben Abramson.

The families yesterday were trying to recover from what they called the "horror" of the accident. Kathy Haddad, the mother of Abramson, said that when the accident occurred, the youths were only four blocks from her home, located in a housing development of Tudor-style town houses near Georgetown. They were to spend the night sleeping in the living room, she said.

Haddad said her son told her that Rostad was walking beside him, on the side near the street, when he was struck by the van. The other three youths were in front, she said.

Rostad was described yesterday by some who knew him as "very personable and funny" and as "a basic average American boy who was very enthusiastic about anything in the sports world - speedboats, sailboats, soccer, football, baseball - anything that was active and moving." His father is an architect.

A passenger in the van with Maubrey, Jose Davis, 25, of Amberst, N.Y., was taken to George Washington University Hospital. Though doctors advised him to stay and be treated for severe head lacerations, Davis refused to do so and left in the early afternoon, a hospital official said.