The accident happened around 10:15 a.m. at Bridge Road and Skippack Trail in Skippack Township.
Police say the driver of a school bus drove through a red light and struck two other vehicles.
The 21 students on the bus at the time of the accident were unharmed.
The view from Chopper 6 HD showed rescuers around the bus with "Atlantic Express" on the side.
A driver and passenger of one of the vehicles were transported to the hospital with minor injuries.
The driver of the bus was cited for the violations.
