By Robin Rieger and Todd Quinones

MANSFIELD, N.J. (CBS) – Seven firefighters were injured, one critically, after an overturned tractor trailer exploded on I-295 in Burlington County.

The initial accident happened at about 1:30 p.m. in the southbound lanes of Interstate 295 near exit 52 in Mansfield, New Jersey.

According to authorities, a tractor trailer lost control and overturned on the highway.

New Jersey State Police say after overturning, the trailer caught fire and pressure from the flames blew the doors open injuring several firefighters.

A medical helicopter transported one firefighter to Helene Fuld Medical Center with a head injury. Authorities say firefighter Brian Richardson, of Florence, New Jersey is listed in critical condition in the Neurointensive Care Unit.

Authorities say six other firefighters were transported to Our Lady of Lourdes Hospital where they were treated and released. One firefighter was admitted with non-life threatening injuries.

The northbound lanes were temporarily closed, but have since reopened.

The right lane remains blocked southbound.

The cause of the accident remains under investigation.