Philadelphia Duck Boat Accident

July 9: An amphibious craft is salvaged from the Delaware River in Philadelphia. An amphibious sightseeing boat that stalled in the Delaware River was knocked over by an oncoming barge Wednesday, spilling 37 people overboard, while two bodies were later found following a search. (AP)

July 7: In this photo released by CBS3 (KYW-TV) in Philadelphia, a barge approaches a stalled duck boat on the Delaware River in Philadelphia. The resulting collision sent all 37 people aboard the smaller amphibious sightseeing boat overboard, while two bodies were later found following a search. (AP Photo/CBS3 KYW-TV)

July 9: Members of a salvage operation are seen as they work to bring up an amphibious craft from the Delaware River in Philadelphia. An amphibious sightseeing boat that stalled in the Delaware River was knocked over by an oncoming barge Wednesday, spilling 37 people overboard while two bodies were later found. (AP)

July 8: Two Hungarian teachers who survived a duck boat crash on Wednesday console one another as they view the site where two of their students went missing on the Delaware River in Philadelphia. The bodies of the two students, Dora Schwendtner and Szablcs Prem, were found on Friday. (AP)

July 8: Philadelphia Mayor Michael Nutter, center, consoles two Hungarian teachers, left and right, who survived a duck boat crash on Wednesday, and an American woman, center top, who served as a host for a Hungarian student group, as they view the site where two of their students went missing on the Delaware River in Philadelphia. The bodies of the two students, Dora Schwendtner and Szablcs Prem, were found on Friday. (AP)

July 7: A rescue vessel is seen on the Delaware River where a tourist boat carrying 37 people overturned when a barge hit it, leaving two Hungarian students unaccounted for until their bodies were discovered of Friday. (AP)

July 8: A member of the Coast Guard holds a wallet fished from the water during a search for two missing tour boat passengers on the Delaware River in Philadelphia on Thursday. The passengers' amphibious craft in which they were riding was struck and sunk by a barge Wednesday.

July 7: A duck boat crew member is pulled from the Delaware River after a tourist boat carrying 37 people overturned when a barge hit it. (AP)

July 9: Chris Herschend, president of Ride the Ducks, makes remarks during a news conference in view of the Benjamin Franklin Bridge and near the scene of Wednesday's collision that occurred between an amphibious craft and a barge on the Delaware River in Philadelphia. (AP)

July 7: This frame grab made from video released by CBS3 (KYW-TV) shows rescuers assisting passengers that were aboard a sightseeing boat that was knocked over by an oncoming barge in the Delaware River in Philadelphia. (AP Photo/CBS3/KWY-TV)

This map locates the typical route of the duck boat that collided with a barge in Philadelphia, along with approximate collision location. (AP)