U.S. Rushes to Rebuild Bosnia Team : Balkans: Secretary of State Christopher cuts short California vacation to return to Washington and assemble peace negotiators. Remains of three American envoys arrive home today.

WASHINGTON —  Secretary of State Warren Christopher cut short his vacation Sunday to return to Washington and rebuild a Bosnia negotiating team devastated by the deaths of three U.S. diplomats in a mountain road accident.

Although President Clinton has vowed that the deaths will not stand in the way of U.S. efforts to end the war in Bosnia-Herzegovina, it is clear that the crash near the capital, Sarajevo, has delayed negotiations for at least a week and deprived the American team of some of its most important members.

Assistant Secretary of State Richard Holbrooke, who headed the team, accompanied the flag-draped caskets of the three men and told reporters at Ramstein Air Base in Germany that he will not return to Bosnia until Aug. 28.

After the accident Saturday, Holbrooke and the surviving members of his team went on to Sarajevo to talk with Bosnian President Alija Izetbegovic. But Holbrooke and the others were apparently too upset to accomplish much.

The three diplomats were killed when their French-driven armored vehicle slipped over the side of the treacherous Mt. Igman road, plunged 400 yards down a ravine and exploded. Holbrooke and other aides were riding in another vehicle in the convoy.

The dead Americans were Robert Frasure, 53, a deputy assistant secretary of state who was Washington’s point man in the Balkans; Joseph Kruzel, 50, a deputy assistant secretary of defense, and Air Force Col. Samuel Nelson Drew, 47, a National Security Council aide. A French soldier serving as a U.N. peacekeeper also died in the crash.

Frasure’s death is seen as a severe loss to the peace effort, because he had been meeting with all the major figures in the Bosnian war for more than a year.

Holbrooke told reporters in Germany, “No one can replace them, but we will reconstitute the team.”

At the State Department, spokeswoman Sondra McCarty told reporters that Christopher intends to meet with Deputy Secretary of State Strobe Talbott and Undersecretary of State Peter Tarnoff as soon as he returns. He plans to confer today with Defense Secretary William J. Perry and National Security Adviser Anthony Lake. Christopher had not been scheduled to return from his California vacation until after Labor Day.

The sudden decision to leave California also means that Christopher will be the senior U.S. official at a brief ceremony at Andrews Air Force Base in Maryland this afternoon when the caskets arrive from Europe.

“Secretary Christopher plans to do everything that he can to press on with the work,” McCarty said.

Many U.N. diplomats have felt that previous attempts at peacemaking have failed because of the inability of negotiators to maintain a momentum as they move from one side of the conflict to another. The loss of momentum is even more acute following the deaths of the three Americans and the sudden halt in negotiations.

The Americans were acting on behalf of the five-nation Contact Group--made up of France, Britain, Russia, Germany and the United States--that has been attempting to mediate the Bosnian war.

The U.S. envoys have been trying to persuade all sides to accept a map that would divide Bosnia almost equally between the Serbs and a federation of Muslims and Croats.

The Serbs, who now control 70% of Bosnia, have refused to accept the map. In the latest round of talks, the U.S. negotiators have been trying to stress to the warring factions that the map can be adjusted to meet their demands.

In Split, the Croatian port where the bodies were taken before being put on a plane for Germany, Gen. Wesley Clark, a member of the American team, described the accident as “a tragedy caused by the circumstances of war, a tragedy on what is clearly the most dangerous road in Europe.”

But Senate Majority Leader Bob Dole of Kansas, a candidate for the Republican presidential nomination, blamed the accident on the Bosnian Serbs, who have fired on planes flying in and out of Sarajevo airport and refused to guarantee safe conduct for the U.S. negotiators through Bosnian Serb lines.

The Americans were on the Mt. Igman road because it is the only route to Sarajevo nominally controlled by Bosnian government forces.

Appearing on the CBS-TV news program “Face the Nation,” Dole said: “Let’s keep in mind the Serbs refused to give them safe passage. They were . . . on a very dangerous highway because of Serb activity. And it seems to me . . . the Serbs . . . were indirectly responsible for the deaths of these three Americans.”

In another accident, the United Nations reported that a British helicopter crashed into the Adriatic Sea while on a training flight Sunday, killing four of five crew members.

One soldier survived by swimming to a Croatian fishing boat, Maj. Gerald Bartlett said. The helicopter was assigned to the new U.N. rapid-reaction force. The cause of the crash was not announced.