Youngsters had been injured when a faculty bus and one other bus collided within the Bue Mountains.
The buses - carrying 15 and 10 folks - crashed into one another at 4:15pm as we speak on the Nice Western Freeway at Solar Valley.
Eleven kids and two adults had been handled by paramedics on the scene, whereas seven had been taken to close by hospitals.
They suffered minor accidents and a male bus driver damage his shoulder.
The accident has triggered a significant backlog of visitors in each instructions.
Police are diverting westbound visitors to Hawkesbury Street, Springwood Street, Darling Causeway and Chifley Street.
Two kids went to Westmead Hospital and 5 others had been taken to Napean Hospital, together with the bus driver.
Investigations into the crash are nonetheless underway.