Search efforts were continuing after a catastrophic capsizing in the Gulf of Mexico, which has been declared a "major marine casualty."
The Seacor Power, a 129-foot commercial ship, was overturned in the middle of a vicious storm Tuesday with 19 people on board. Authorities have not confirmed whether weather caused the incident.
Six crew members were initially rescued on the open water, and one person was found dead the next day. Families of the 12 remaining crew members were still waiting for news.
"While search efforts for the crew are continuing, the incident has been declared a major marine casualty," the Coast Guard said in a news release. It said it is "leading a preliminary investigation and the National Transportation Safety Board will be joining in that effort."
The Coast Guard said divers were able to knock on the hull of the vessel Thursday but did not hear a response. It said reports of communication between emergency responders and crew members potentially on board in "air pockets" were unfounded.
The search will resume Friday, it said.
David Ledet was identified Thursday as the person who was found unresponsive on the surface of the water, the Lafourche Parish coroner confirmed. Ledet was the captain of the ship, The Times-Picayune and The New Orleans Advocate reported. A former crew member said on social media that Ledet had over 15 years of experience.
"I'm scared and I'm devastated and I'm broken," said Darra Morales, whose son was aboard the ship. "I just want my son to come home to his children."
Morales' son is Chaz Morales, 37, a father of three, who she said is a crane operator for the Seacor Power.
Marion Cuyler, his fiancée, said: "It shouldn't have left. That's what everybody is saying. Why did it leave? Who gave the orders for this boat to leave in this type of weather? Gale-force winds, it shouldn't have left."
Cuyler said Morales has worked as a crane operator for almost 20 years. The couple were texting throughout the day and talked about how badly the weather had deteriorated.
"They knew the weather was bad, obviously. It was bad out here that day," Cuyler said.
Chett Chiasson, the executive director of Port Fourchon, said, "No one could have predicted 110 mph winds coming our way when there's not a hurricane in the Gulf."
Chiasson, who described the marine community as "brethren," said it was no surprise that private boats and good Samaritans jumped in to help when a wave of mayday calls came in Tuesday afternoon, ultimately leading to the rescues of several stranded crew members.
As for the search-and-rescue efforts, the "Coast Guard air and surface assets continued to search overnight, and the search will continue throughout the day," the Coast Guard said.
Coast Guard crews have searched for a combined 70 hours covering about 6,380 square miles, "an area roughly the size of Hawaii," the Coast Guard said in a news release.
The National Weather Service issued a flash flood watch through Saturday morning for parts of southeast Louisiana, meaning conditions will remain challenging for rescue teams.
Seacor did not respond to multiple requests for comment.