At least 19 children and one employee were sent to the hospital with injuries after a SUV crashed into a day care center in Anderson, California, on Thursday afternoon, police said.

Two children had to be taken to the ICU, according to hospital officials. One of the injured children was trapped underneath the vehicle, police said.

The 19 children taken to hospitals comprised all of the kids in the day care at the time of the crash, according to Anderson police, adding there were also two staff members working when the Suzuki SUV hit the side of the building.

The vehicle struck the daycare at around 2:30 p.m. right in the center of the daycare where all the children were located at the time.

The driver of the SUV was an Anderson woman, but police did not identify her. Authorities determined she was not under the influence of drugs or alcohol.

She was released after providing officers with a statement, according to authorities. The cause of the crash was still under investigation Thursday night.

Anderson police declared the crash a “Mass Casualty Incident” because of the potential number of injured people at the day care.