'Swamp People' Involved in Explosive 5-Car Pile-Up [PHOTOS]

"Swamp People" gator hunters Tommy Chauvin and his stepfather Joe LaFont are lucky to be alive -- after the pair was involved in a NASTY 5-car pile-up yesterday near the Arkansas-Louisiana state line.

Tommy and Joe were not hurt -- but according to reports, three other people involved in the accident suffered serious injuries. There were no fatalities.

According to reports, four vehicles -- including Chauvin and LaFont's -- had come to a stop for a flagman directing traffic around a construction site on the highway.

Everything was hunky dory -- until a fifth vehicle (a giant tractor-trailer) came careening along and smashed into the back of another truck waiting in line.

The accident caused a massive pile-up -- but the biggest casualty ... a bunch of "Swamp People" merch that spilled out of Tommy and Joe's truck ... and scattered across the highway.