NTSB: Pennsylvania Duck Boat Radioed Tug, Got no Response

In the minutes before a barge rammed into an idled duck boat, dumping more than 30 tourists overboard and leaving two people dead, radio calls from the tourist craft to the tug boat pushing the barge went unanswered, the National Transportation Safety Board said Monday.

The crew of the tug Caribbean Sea included a master, a mate, an engineer and two deck hands, the NTSB said in a news release. One mate "exercised his Fifth Amendment right and refused to meet with investigators" over the weekend, it said.

One of the deck hands was also asleep at the time, but it wasn't immediately clear whether he was on the clock.

The duck boat's mate and a deck hand both said their radio calls to the tug "received no response," the NTSB said. The agency said it also interviewed others aboard different boats who said they "recalled hearing" the duck boat's radio calls.

The amphibious duck boats are a popular way for tourists to see the sights of Philadelphia from both land and water. The duck boat in Wednesday's accident had entered the water when an apparent mechanical problem left it adrift in the path of the barge.

The collision flipped the boat and dumped 35 passengers and two crew members into the Delaware. Two Hungarians visiting Philadelphia as part of a language program, 20-year-old Szabolcs Prem and 16-year-old Dora Schwendtner, were missing for two days before their bodies were found.