Motorists are being advised to avoid the M1 Princes Motorway in west Wollongong after a multi-vehicle crash near Mount Keira Road.
NSW Police have confirmed that two people have died in the smash, which involved at least two trucks and three cars.
At least one vehicle is on fire.
A major emergency operation is now underway, with all southbound lanes and two northbound lanes closed near Mount Kiera Road overpass.
Motorists are being diverted into Mount Ousley Road and the Princes Highway, and Transport NSW are urging anyone who can to avoid the area.