(CNN)Four children ages 3 and 4 were injured when a woman crashed her car through the window of a day care center, Pennsylvania authorities say.
The black BMW on Thursday traveled through a classroom of the Children of America Educational Childcare center before stopping at a back wall, the Bucks County Attorney's Office said in a statement.
Four children were taken to the hospital, one with serious injuries, the statement said.
The driver had minor injuries, was treated and remains hospitalized, the statement said.
The injured children were 3 and 4 years old, said James O'Malley, spokesman for the district attorney's office, on Friday
O'Malley said the crash is under investigation. He told CNN the woman was working as a delivery driver.
At the time of the crash -- about 1:30 p.m. -- about 17 children were in the room and about 79 total were in the building .
All were accounted for and reunited with their families, the statement said.