A multi-vehicle crash involving two cars and two tractor trailers, one of which overturned, caused major traffic problems on the New Jersey Turnpike in South Jersey this morning.  A second, later crash, also snarled traffic further up the road.

In the first accident, a trailer flipped shortly after 8 a.m. in the northbound lane, between exits 3 and 4 near Cherry Hill, after it was involved in the multi-vehicle crash, according to New Jersey State Police. It was not clear if this morning's weather was a factor.

At least one person was seriously injured and a medical helicopter was requested for the crash scene at mile marker 29.9. A resulting fuel spill further hampered efforts to reopen and clear the road.

At one point, there was a four mile backup as the driver remained entrapped and lanes were blocked. Authorities were warning motorists to expect major delays.

A separate crash, further north, but in the southbound lanes involving a box truck only worsened the situation as all lanes but the shoulder were shutdown.  That crash was cleared about 11:15 am.

Check back for details as they develop.