The crash happened around 1:00 p.m. Wednesday in the southbound lanes of the Roosevelt Boulevard near Fox Street.
SEPTA officials tell Action News that the driver claims the bus had been cut off by another vehicle.
In an attempt to prevent a collision, the driver claimed to have swerved and caused the bus to overturn onto the trunk of another vehicle.
A third vehicle was also involved. That car overturned as a result of the crash.
The bus' operator, a passenger and the passenger's caretaker have all been taken to the hospital in stable condition. They are described as a 29-year-old female, a 23-year-old female and 86-year-old female. All were transported to the hospital in stable condition.
An unrelated crash also apparently occurred at the scene after the initial crash. The view from Chopper 6 HD showed a red SUV that collided with the rear of a responding fire engine. That collision appears to be minor.