Sixteen people were taken to the hospital today, at least two in serious condition, after they were hurt in a crash between a hotel shuttle bus and a tractor-trailer near Atlanta's airport, officials said. The morning crash occurred on the road that loops around Hartsfield-Jackson Atlanta International, the world's busiest airport. It appears the shuttle struck the side of a tractor-trailer that was attempting a U-turn. "I don't believe any of the passengers were wearing seat belts on the shuttle bus, so they were all thrown," said a police sergeant. Marks on the road indicate the bus skidded about 158 feet before the impact. It wasn't immediately clear whether any traffic laws were violated.