APR 4, 2007 4:06 AM US/PACIFIC 3 KILLED IN SINGLE-CAR CRASH IN WHITTIER, CALIFORNIA THREE PEOPLE WERE KILLED WHEN A CAR LOST CONTROL IN WHITTIER AND SLAMMED INTO A TREE. POLICE SAID WEDNESDAY THAT THE VICTIMS OF A SOLO-VEHICLE CRASH IN WHITTIER THAT LEFT THREE PEOPLE DEAD AND TWO OTHERS HOSPITALIZED RANGED IN AGE FROM 18 TO THEIR EARLY 20S. THE CRASH OCCURRED ABOUT 7 P.M. TUESDAY ON COLIMA ROAD NORTH OF MAR VISTA STREET, WHITTIER POLICE OFFICER DIANA SALAZAR SAID. JENNIFER UNZUETA, ALBERT VELASQUEZ AND JOSH GUTIERREZ WERE KILLED, SALAZAR SAID. UNZUETA WAS AN 18-YEAR-OLD WHITTIER RESIDENT; VELASQUEZ, 19, WAS FROM WHITTIER; AND GUTIERREZ WAS A 19-YEAR-OLD PICO RIVERA RESIDENT, ACCORDING TO THE CORONER'S OFFICE. THE DRIVER, AN 18-YEAR-OLD WOMAN IDENTIFIED AS XENIA GUERRA, REMAINED HOSPITALIZED IN STABLE CONDITION AT UCI MEDICAL CENTER, SALAZAR SAID. HECTOR SAENZ, IN HIS EARLY 20S, WAS AIRLIFTED TO COUNTY-USC MEDICAL CENTER, AND WAS HOSPITALIZED IN STABLE CONDITION, SALAZAR SAID. GUERRA, WHO HAD FOUR PASSENGERS IN THE TOYOTA SCION, TOLD POLICE SHE LOST CONTROL OF THE COMPACT CAR. THERE WERE NO WITNESSES, BUT SALAZAR SAID THE TOYOTA WAS COMING DOWN A HILL FROM A WILDERNESS AREA WHEN THE ACCIDENT OCCURRED. IT WAS NOT CLEAR WHAT CAUSED THE CRASH, BUT DRIVERS OFTEN COME DOWN THE HILL AT DANGEROUSLY HIGH SPEEDS, SALAZAR SAID. THE SCENE WAS CLEARED AROUND 3:10 A.M. WEDNESDAY, WHITTIER POLICE SGT. A. RUIZ SAID.