Firefighters found themselves on a slippery slope Jan. 8 after two tractor-trailer rigs collided, and the ensuing fire fully involved both vehicles approaching the top of South Mountain near the Summit Lawn exit of Interstate 78 shortly after 11 a.m.

A dark column of smoke could be seen for miles and the accident shut down the interstate roadway for nearly two hours.

Water used by firefighters to fight the fire immediately flashed to ice in the intense cold, creating a slippery surface sending many firefighters tumbling to the road's surface and making their efforts doubly hazardous.

State police said the accident occurred when a tractor-trailer hauling a cargo of canned black beans slowed to about 10 miles an hour as it labored up the steep grade.

The rig was struck from behind by another rig. The second rig's engine compartment was wedged under the trailer of the first unit when the cab caught fire, engulfing the rear of the trailer. Both units were engulfed in flames when the first Salisbury firefighters arrived on the scene.

Eastern Salisbury Fire Department's tanker truck was first on the scene, arriving by driving north in the southbound lanes of the roadway. ESFD Deputy Chief Kyle Mertl and Firefighter Andrew DeMasi hooked a hoseline to the tanker's pump and attacked the fire in the rear of the first trailer.

Arriving shortly thereafter, an engine from Western Salisbury Fire Department, which had to dodge traffic and come up the shoulder of the vehicle-clogged roadway, was able to attack the fire in the cab area of the second rig.

WSFD Firefighter Ramon Deeb was on the nozzle of a hoseline only a few feet from the intense fire, backed up by WSFD firefighters Jonathan Al-Khal and Michael Abraham. WSFD Deputy Chief Jason Faryniak was incident command officer at the scene.

All the firefighters had to use self-contained breathing apparatus because of heavy toxic smoke from the burning rigs.

Small explosions from inside the first trailer sounded like a giant popcorn popper. The pops were later found to be exploding cans of beans.

State police from the Fogelsville barracks said Albert W. Couch, of Antioch, Tenn., was driving the tractor-trailer that rear-ended the rig driven by Luis N. Nunez, of Union City, N.J.

When Couch's truck caught fire, a passer-by stopped and helped to free Couch and his passenger, Brandon E. Daniels, of Hermitage, Tenn., police said.

As Couch's cab became engulfed in flames, the fire spread to the rear of Nunez' trailer.

Troy Richards, of Gloucester County, Va., a driver for the J.B. Hunt trucking company, said he went to help after he saw the collision and fire. He pulled the driver out of the truck and sat him on the ground just as the truck burst into flames.

The two drivers and two passengers were transported to Lehigh Valley Hospital with non-life-threatening injuries, police said.

Also assisting at the scene were Upper Saucon Ambulance Corps, an Allentown EMS unit, and Emmaus Ambulance Corps.

Lower Milford Fire Company and Fogelsville Fire Company sent tanker units to the scene because no water supply was available along the highway.

Heavy duty wreckers from Hauser Trucking Service were brought to the scene to separate the two rigs and haul them away.

A PennDOT truck spread salt on the roadway before one-lane of traffic was opened around the accident shortly before 1 p.m.

Heavy traffic clogged secondary roads after police closed the interstate at Cedar Crest Boulevard and Lehigh Street so firefighters could work.