DES MOINES, Iowa (AP) — Police say no children were hurt when a sport utility vehicle crashed into Willard Elementary School in Des Moines.

The Des Moines Register says the crash happened shortly before 2 p.m. Friday when the vehicle, which was headed south on East 30th Street, left the road and hit the east side of the school. Des Moines police spokesman Sgt. Paul Parizek says police are investigating the cause of the crash.

The driver suffered a minor head injury but was able to walk to an ambulance. Parizek says the driver told officer that the brakes on the SUV failed.

Parizek says the crash “didn’t even knock books off the bookshelves” on the other side of the school’s brick wall that was hit.