The person trapped in a vehicle has since been freed.
Traffic is heavy in both directions, with motorists advised to avoid the area.
All northbound lanes have re-opened.
Route 458 buses are only operating between Burwood and Rhodes, with five stops missed and delayed up to 40 minutes.
Route M41 buses are diverting to miss the area, with two stops skipped and delays of 60 minutes.
Motorists in the area are advised to allow plenty of travel time.
In breaking news, there is a huge crash in Ryde affecting traffic going both ways on Church Street at Junction Road.
Two buses, one truck and six cars have been involved, according to NSW Ambulance.
One female is trapped and unconscious, with crews working to free her.
Six other patients have been injured but are in a stable condition.
Six ambulance crews are on the scene, with a helicopter also on the way.
At 11.04am, it was confirmed that the two of three northbound lanes that were closed have since re-opened.
More to come.