PHILADELPHIA (AP) — Hope faded for finding two tour boat passengers alive Thursday, a day after the amphibious craft they were riding in was struck and sunk by a barge in the Delaware River, spilling them and other passengers into the murky waters, searchers said.

A search for the missing duck boat passengers resumed in the morning near Philadelphia’s Penn’s Landing, with boats searching the surface and using sonar, but conditions were too dangerous to send divers underwater Thursday.