An airboat carrying 16 tourists through the swamps here capsized Saturday evening, critically injuring several people, authorities said.
The accident occurred in the swamps surrounding Lake Salvador, about 22 miles south of New Orleans. It is an area where tourists flock to see wildlife that includes alligators -- often drawn into sight by chicken meat dangling from poles on the boats.
The Coast Guard initially said at least one person was dead, but later it said that could not be confirmed.
Jefferson Parish sheriff's spokesman Col. John Fortunato, whose department also responded, said: "It was thought someone had passed, but no one has been confirmed deceased as of yet."
He said all passengers and the captain were found and taken to hospitals in the New Orleans area, three in critical condition.
There was no immediate word on the identities of the victims.
The capsized boat -- a flat-bottom aluminum vessel powered by a large fan mounted on the stern -- belongs to Louisiana Swamp Tours.
"I've always felt as though we've been safe in operation," said tour operator Milton Walker Jr. "I never thought something like this could happen."
Walker said the boat, because it was full, was likely not going faster than 35 mph.