The US transportation safety authority on Monday confirmed that wreckage found at the bottom of the ocean is that of a ship that went missing four weeks ago during Hurricane Joaquin, dpa reported. The National Transportation Safety Board (NTSB) said the wreckage found Saturday at a depth of about 4,500 metres in the vicinity of the last known position of the El Faro is the cargo ship. The 224-metre-long El Faro was bound for San Juan, Puerto Rico with a crew of 28 US citizens and five Poles, when last heard from October 1 near the Bahamas, as Joaquin was gaining strength over the archipelago. The NTSB said a survey of the area and vessel would continue. The authority said previously that they hoped to locate the ship's black box, which might offer clues to explain what went wrong. All 33 people aboard the vessel have been declared dead, but only one body has been found. A search team on board the US Apache found the wreckage using sonar equipment towed by the ship. Navy specialists then sent down a remotely operated vehicle to survey and confirm the identity of the wreckage. President Barack Obama expressed condolences to the families of the 33 people who died. At least 12 of the families have sued the shipping company for millions of dollars in damages. They say the El Faro was not seaworthy.