A Ride the Ducks boat stalled on the Delaware River Sunday afternoon, on the eve of a trial stemming from the 2010 accident in which a large barge hit a duck vessel stopped on the water, killing two passengers.

All 26 passengers and two crew members were towed safely to shore, the company said.

After the 2010 accident, in which two Hungarian students died when a barge hit a stalled Ride the Ducks boat, the company, working with the Coast Guard, created a safety plan that included always having a tow boat nearby. The duck boats also now use a much shorter route that company officials have said is designed to keep their vessels far away from larger boats.

A mechanical problem caused the boat to stop on the water Sunday, and a company spokesman said no cause has been determined.

"Like any other mechanical vehicle, vessels may sometimes stall. The important point was that our safety procedures worked just as they had been planned and practiced. At no time were passengers in harm's way," said Greg Blumenthal, RTD Philadelphia general manager. "It's too early to know the exact cause of the stall; a review will be done to determine the cause of the service disruption."