Five teenagers escaped after a crash on the M23.
The car they were travelling in ended up on its roof after the crash on the northbound carriageway between junctions 11 and 10 near Crawley.
No-one was trapped in the crash, which happened at about 8.45pm on Monday.
Two of the teenagers, who were all 17 years old, were taken to hospital.
Anyone who saw what happens is asked to call Sussex Police on 0845 6070999.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here