A 20-year-old Maryland man awaits sentencing for crashing his car at high speed into a vehicle carrying a family on their way to a high school play.

The Montgomery County state's attorney's office announced in a statement that Olgucan Atakoglu of Potomac pleaded guilty Monday to three counts of vehicular manslaughter. Prosecutors say investigators surmise Atakoglu was driving about 115 mph moments before the crash in a 45 mph zone.

Police said 52-year-old Michael Buarque De Macedo, 53-year-old Alessandra Buarque De Macedo and their son, 18-year-old Thomas, were killed in the Feb. 27 crash. Their 15-year-old daughter, Helena, was hospitalized with life-threatening injuries. Walt Whitman High School principal Alan Goodwin said the family was heading to a school play.

Atakoglu was ordered held without bond until his Nov. 7 sentencing.