Pacific Daily News says the two-vehicle collision occurred Sunday in Yigo.
Those killed are identified as 10-year-old Mya Ann Neth, 64-year-old Damiano Neth of Yigo, 63-year-old Markarita Neth and 61-year-old Ruhney Hadley of Mangilao.
The survivor is identified as 22-year-old Kervina Hikuta. Police say a Chevrolet Silverado driven by Hadley was southbound along Route 15 when it collided head-on with a northbound Toyota Corolla occupied by the four others and driven by Damiano Neth.
Hikuta was taken to Guam Memorial Hospital, where she was listed in serious condition.