The older woman is in a critical but stable condition at Liverpool Hospital, and the teenager has been transferred to Westmead Children’s Hospital.
The car’s male driver, also in his 50s, was taken to hospital in a stable condition.
The two vehicles collided on Memorial Avenue in Liverpool, with NSW Ambulance saying it was “mayhem” when paramedics arrived on the scene just after 11am on Saturday. Some paramedics are reportedly seeking counselling.
Two bus passengers, a 14-year-old boy and woman in her 60s, were also taken to hospital, but the bus’s driver escaped injury.
“This is a horror crash on our wet roads today. It was mayhem when paramedics arrived on scene,” NSW Ambulance Inspector John Brotherhood said.
“These wet conditions on our roads are unprecedented and have the potential to be life-threatening.
“It takes one single thing to go wrong and your vehicle can become a weapon. Look after each other in these conditions.”