TALLULAH, La. (AP) _ A church bus taking senior citizens on a tour of historical sites around the East slammed into a cotton-hauling tractor-trailer parked on the shoulder of a highway Monday, killing six people and injuring at least nine.

The bus driver survived the wreck and told investigators he may have fallen asleep at the wheel before crashing into the truck, state police Sgt. C. K. Thompson said.

Fifteen people were on the bus when it crashed around 11 a.m. on Interstate 20 in northeastern Louisiana. The truck driver, who had pulled onto the shoulder to check his brakes, suffered minor head and neck injuries.

State police initially said six people had died, but later revised the death toll down to five. They then changed the number back to six.

The passengers were headed toward Vicksburg, Miss., on the second day of what was to have been a 16-day trip sponsored by their Baptist church in Texas, state police trooper Julie Lewis said.

The ``senior ambassador tour'' was to include visits to a Mercedes-Benz factory in Alabama, the Grand Ole Opry in Nashville and the Civil War battlefield in Gettysburg, Pa. Each passenger paid $960 for the trip, sponsored by the First Baptist Church of Eldorado, Texas, a town of about 2,000 people some 160 miles northwest of San Antonio.

The bus and the truck remained upright on the side of the road after the crash, but the front end of the bus was demolished _ pushed up under the rear of the 18-wheeler's trailer, its engine driven back against the steering wheel by the impact. Bales of cotton, seats from the bus, pillows and clothing littered the highway.

Emergency crews said no passenger was ejected but some were thrown partly out of the open side of the bus.

Traffic in the eastbound lane of I-20 was shut down for about 20 miles between Tallulah and Waverly.

Louisiana State Police have again revised the death toll in the I-20 bus crash _ it is now six again. They provided no explanation for the latest revision. A writethru will move shortly.

The AP, New Orleans