Twenty people were initially rescued, while the four crew members were missing. Three of the four were rescued on Monday afternoon, the Coast Guard said.

“I know they looked super happy to be outside of that space,” Capt. John Reed of the Coast Guard said at an afternoon news conference, referring to the three crew members. He described their conditions as “relatively good.”

The three crew members were extracted from the ship through a two-foot-by-three-foot hole that was created in three-inch increments, Capt. Reed said. They were located by rescue workers, who tapped on the outside of the ship and listened for a response.

“They would do three or four taps or more, and eventually they got tap-backs,” Capt. Reed said. The crew’s ability to follow the returning sounds is “a pretty fascinating story,” he added.

The remaining crew member was trapped behind glass in an engineering control room. He was rescued a couple of hours after the three others.