A packed double-decker Megabus blew a tire and slammed into an Illinois interstate bridge support pillar Thursday, hurtling screaming passengers from their seats and leaving at least one person dead and more than two dozen injured, officials said.

Illinois State Police Trooper Doug Francis confirmed one person died in the afternoon wreck of the discount charter bus, which was traveling between Chicago and Kansas City.

At least four people were flown by helicopter to a trauma center. Hospitals treated more than 20 other patients from the crash, which left the bus sitting with its crumpled front end smashed up against the bridge support. Rescue crews climbed ladders to reach those trapped inside, while others tended to injuries along the side of Interstate 55.

Megabus spokeswoman Amanda Byers said the bus was at full capacity, carrying 81 passengers, when it crashed near Litchfield, about 55 miles northeast of St. Louis. It left from Chicago and was to stop in St. Louis and Columbia, Mo., before arriving in Kansas City.

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