DUNLAP, Tenn. (AP) _ A tractor-trailer slammed into participants at the ``World's Longest Yard Sale'' Thursday night, killing at least two people and injuring 15, authorities said.

The trucker lost control of his rig in this small town about 25 miles north of Chattanooga, Highway Patrol Lt. John Collins said.

``People were set up for this yard sale ... The truck got over into the sand and into some campers that were there with the flea market,'' Collins said.

The tractor-trailer rig collided with another vehicle before slamming into the line of exhibitors, Collins said.

Ten vehicles, including some parked along the highway, were involved in the crash, he said.

Four people were flown by helicopter to Erlanger Medical Center in Chattanooga. The rest of the injured were taken to area hospitals, Collins said.

The victims were along a 450-mile route that stretched from Gadsden, Ala., through Georgia and Tennessee to Covington, Ky.

Thousands were expected to brave traffic jams and sweltering heat in search of a bargain.

The event began Thursday and was to run through Sunday along U.S. Highway 127, with everything from hubcaps to antique china on sale.

The outdoor sale began 11 years ago when Fentress County, in northeastern Tennessee, sought a way to draw tourists off the interstate and into smaller communities. The event grew steadily and last year drew more than 30,000 people and more than 3,000 vendors.

Vendors rent space from homeowners and businesses, usually paying less than $100 for a prime spot.