Two teens were trapped in their car after it hit a power pole at Wollondilly on Saturday.
The accident happened at 4.30pm on Silverdale Road.
The driver and passenger, both aged 19, were freed from the Subaru by Fire and Rescue NSW and the Rural Fire Service.
They were both taken to Liverpool Hospital, with one suffering a broken leg and pelvis.
The St Marys Local Area Command is investigating the crash.