Police are investigating the cause of a head-on crash in Sudbury involving a school bus.
The bus, carrying about 25 students from the Algonquin Regional High School girls rugby team, was traveling on Concord Road around 4 p.m. when the crash with a sedan occurred, according to Sudbury police.
Police said the driver of the sedan, a 73-year-old Sudbury woman, was trapped inside the car when first responders arrived on the scene. She was extricated using the Jaws of Life and transported to Beth Israel Deaconess Medical Center in Boston with serious injuries.
Police said about 9 students, aged 15 to 18, and the bus driver, a 43-year-old woman from Hudson, received minor injuries in the crash and were transported to MetroWest Medical Center in Framingham for treatment. The two coaches on the bus were not injured.
The team was on its way to a game against Lincoln-Sudbury Regional High School.