A commercial submarine disappeared near the site of the Titanic wreck on Monday, with tourists on board. The Guardian newspaper reported that five people were on the vessel at the time of its disappearance.

The tourist attraction is operated by a company called OceanGate Expeditions. The BBC and The New York Times quoted the U.S. Coast Guard, which said a search and rescue operation has been launched.

"Our entire focus is on the crewmembers in the submersible and their families,” OceanGate Expeditions said in a statement. Before its website crashed, it said an expedition to the Titanic was "currently underway.”

The company added that it was "deeply thankful for the extensive assistance we have received from several government agencies and deep sea companies in our efforts to reestablish contact with the submersible." 

The Titanic sank in the Atlantic Ocean on April 15, 1912, after hitting an iceberg. Over 1,500 people were killed, out of 2,224 passengers, on its maiden voyage from the UK to New York.

The wreck, discovered 37 years ago, was found roughly 13,000 feet deep on the Atlantic floor, some 400 nautical miles from Newfoundland, Canada.