Rough seas off Italy's Tuscan coast forced a delay in the planned start of the operation to remove a half-million gallons of fuel from the grounded Costa Concordia. (AP)

But on the same day an Italian court refused to lift the house arrest order for the ship’s captain — who is under investigation on suspicion of manslaughter, causing a shipwreck and abandoning the vessel before all passengers were evacuated — National Geographic Channel pounced.

NatGeo announced Tuesday that it had hired the producers of the quick-turnaround British documentary “Terror at Sea: The Sinking of the Concordia” — which already aired on the United Kingdom’s Channel 4 — to rework it for the United States under the name “Italian Cruise Ship Disaster: The Untold Stories.” It will air Sunday, NatGeo announced.

And that beats to air by one week Discovery’s premiere of “Cruise Ship Disaster: Inside the Concordia.”

“Just announced! National Geographic Channel to air first U.S. documentary detailing the Italian cruise ship disaster moment-by-moment,” NatGeo bragged Tuesday.

Discovery’s Costa Concordia project will be a very focused forensic investigation that uses experts from the Massachusetts Maritime Academy and that includes survivor stories and eyewitness accounts.

Discovery crews will be covering the teams charged with figuring out how to salvage a shipping vessel larger than the Titanic. The Discovery docu will address such questions as: What happened at the time of the accident? What role did Capt. Francesco Schettin play? How did the crew evacuate the ship? What are the mechanics of searching the site while guarding the waters against environmental damage? What lies next for the massive, unprecedented salvage mission? And will salvage teams even be able to save the ship and successfully dismantle its once mighty hull and frame?

“With so many unanswered questions, Discovery will piece together not only the immediate events, but the bigger story of what comes next in recovery and restoration,” Nancy Daniels, executive VP of production and development for Discovery Channel, said recently.

NatGeo’s Concordia program promises to detail the sinking in a “still raw” account, told primarily through the eyes of those who experienced it, who are also American. “American survivors tell their haunting story in depth and share exclusive home video footage,” NatGeo promised.

For the NatGeo telecast, the British documentary’s non-American interviews have been swapped out for American ones: Sameer and Divya Sharma from Massachusetts were celebrating their fifth wedding anniversary, and 18-year-old Amanda Warrick, who was traveling with her elder brothers, tossed out the idea on the Friday-the-13th departure date that “something’s gonna happen.”

When the ship hit the rocks, “At first there was a tilt and a shake of the ship — that’s when tables and glasses started crashing. I was kind of in shock. I remember immediately standing up and looking at my brothers. I was just kind of speechless and silent,” Amanda says in the docu.

“It’s really an experiential look at this — what it would be like if you were on” the ship, Michael Cascio, NatGeo exec VP of programming, told The TV Column. “We thought our contribution would be best handled by airing accounts of people who were on it,” including “lots of user-generated video.”

“We’ve used this kind of witness approach before,” Cascio said, noting the channel’s premiere April 13 of the documentary “Witness: Disaster in Japan,” about that country’s earthquake, tsunami and nuclear power plant emergency. That docu aired one month after that disaster.

“When we did the Japanese disaster, and some of these other disasters — it’s a niche to be filled — the news networks have done their bits and pieces, but nobody has put it together,” he said.