CHERRY HILL, N.J. (CBS) — Two separate crashes on the New Jersey Turnpike Wednesday morning injured at least one person and snarled traffic for hours.

The first accident happened shortly after 8 a.m. in the northbound lanes of the Turnpike near Route 73 in Cherry Hill.

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A tanker truck went off the roadway and ended up on its side. Chopper 3 was over the scene where it showed emergency personnel extricating the driver. The driver was then air-lifted to a local hospital in an unknown condition.

A short distance behind the tanker truck, a tractor-trailer crashed and blocked the right lane of traffic.

Officers say a tire came free from an unknown vehicle and slammed into one of the tractor-trailers and triggered a chain reaction crash.

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New Jersey State Police say at least one person was seriously injured. Two cars were also involved in the crash.

The second accident happened a time short time later in the southbound lanes, only a short distance away. In this accident, a tractor-trailer overturned near at mile marker 32.5 and blocked all lanes of traffic for some time this morning. All southbound lanes were reopened just before 11 a.m.

The NJSP is urging motorists to avoid both locations as major delays are expected.

The crashes remain under investigation.

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