Prosecutors declined to file a vehicular manslaughter charge against Grammy-nominated soul singer Luther Vandross. District attorney spokesman Al Albergate said police discussed the case with a prosecutor, but the lawyer decided that no charges could be filed without further investigation. One of Vandross' passengers, Lawrence Salvemini, 27, of West Hollywood, was killed Sunday when the entertainer's Mercedes-Benz drifted across the center line on Laurel Canyon Boulevard and smashed into two oncoming vehicles. Police said they found no evidence that the singer was under the influence of alcohol or drugs at the time of the accident. A spokesman at Cedars-Sinai Medical Center said Vandross, 34, will be released today.