SAN DIEGO — A Sig Alert was issued along the northbound Interstate 5 through Carlsbad following a multi-car crash near Palomar Airport Road.

Reports of the collision came in around 1:36 p.m., notifying the Carlsbad Fire Department of a vehicle on fire on the freeway.

According to department logs from California Highway Patrol, six cars were involved in the collision: three smaller vehicles, two vans and a semi-truck.

SkyFOX aerial footage showed significant damage to the front of at least two of the vehicles involved in the incident. CHP described one of the vehicles as nearly ripped in half.

It is unknown at this time what caused the crash. No injuries have been confirmed by authorities.

All lanes were blocked following the crash, with a single lane open for through traffic. As of 5:39 p.m. Friday, the lanes have been reopened.

The Sig Alert has also been cancelled, but the traffic tracking system indicates that the roadway along the I-5 through Carlsbad remains backed-up in the area.