NEW ORLEANS (AP) _ A beer van lurched into the crowd during a St. Patrick's Day parade through the French Quarter, killing one person and injuring 20 others.

The parade had just turned onto Bourbon Street when the van _ near the back of the parade _ suddenly accelerated from a stopped position and plowed into the crowd Friday night, knocking people down and rolling over bodies.

``It was pretty horrifying,'' said Michael Foto of New Orleans. ``It was bouncing and rolling over people. It happened so fast you couldn't react.''

A man riding on top of the van tossing beads was thrown off. Hank Hinricks, who was with Foto, said the van started backing up and he jumped up to the cab and told the driver to turn off the ignition. Foto said a woman sitting on the passenger side had no idea why the van accelerated.

Police had few details, and the victims were not immediately identified.

Bourbon Street is usually blocked to traffic, jammed with drinking pedestrians. But there were no barricades Friday and the small parade wound through the French Quarter crowds.

Trish Burke, a tourist from New York City, said the crowds were in the street, but there was no problem because the parade was moving so slowly.

Sam Alassal, manager of a nearby cafe, said he didn't see the accident but heard it.

``I heard like a noise, like something blew up or a gunshot,'' Alassal said. ``I thought someone was shooting.''