Three siblings were killed and a fourth child was seriously injured when they were hit by a car in Indiana Tuesday.
Police say it happened as the children were boarding their school bus while the stop arm was extended.
A 24-year-old woman identified by police as Alyssa Shepard driving a car in the opposite direction failed to stop and hit the children and killed 6-year-old twin boys Xzavier and Mason Ingle and their 9-year-old sister, Alivia.
An 11-year-old walking with them was airlifted in critical condition.
The injured child was not related to the siblings.
School officials say they have sent counselors to meet with parents, students and staff.
Shepard is in custody and facing a number of charges, including three counts of reckless homicide.