A Turkish cargo ship sinks in 11 minutes off Istanbul. Ten crew are missing.

The Tugberk Imamoglu went down in about 11 minutes after it struck the tanker Alsu in the Sea of Marmara before dawn on 2 September. Transport Minister Abdulkadir Uraloglu said the captain reported the collision at 3:15 a.m. The emergency call reached the directorate at 3:26 a.m. By the time the first rescue craft arrived at 4:10 a.m., the cargo ship was gone. Ten people were on board, the captain and nine crew, all Turkish. An empty lifeboat and life buoys were found. No one answered ship radios or mobile phones.

The collision happened about 18 nautical miles off Silivri, on the western edge of Istanbul province, or about 32 kilometres south of the suburb by the governor’s first account. Alsu, flying the Turkish flag, was empty. Early statements said it carried 3,000 tonnes of motor oil. The maritime directorate later corrected that. The tanker stayed afloat and appeared undamaged. The Tugberk Imamoglu was a 90-metre, 1990-built multi-purpose general cargo ship, according to VesselFinder. It was carrying 4,200 tonnes of rolled sheet metal and rebar.

That cargo helps explain the speed of the sinking. Rolled steel is dense. A hull opened below the waterline does not give a 35-year-old coaster much reserve buoyancy. Uraloglu used the word “rapidly.” The 11-minute clock is his arithmetic from the captain’s time to the emergency signal. Search teams treated the wreck as a missing-persons case from the first hour, not as a salvage job that might still produce survivors on deck.

Two helicopters and 12 search and rescue vessels worked the site through Wednesday. Units from the coast guard’s Marmara and Bosphorus Command were among them. The directorate said it believed the ship had sunk because it answered neither radio nor telephone. Debris confirmed the identification. Names of the ten were not in the first public statements.

The Sea of Marmara is a waiting room for the Bosporus. Ships anchor there for days before a northbound or southbound slot. Traffic is heavy, lights are many, and collisions in the approaches to Istanbul are a known risk rather than a rare shock. What is rare is a total loss in 11 minutes with no one off the ship. The empty lifeboat is the detail that will sit in the accident file. Either the crew had no time to board it, or they boarded it and did not stay with it. Divers and sonar will have to answer that once the wreck is marked.

Alsu’s role will be the other half of the inquiry. An empty tanker should manoeuvre more easily than a laden one. Investigators will want the course recorder, the watch composition, and whether either bridge was running a reduced night watch. The directorate has not released those records. Until it does, the public facts stop at time, place, cargo, flag and the empty boat.

Rolled steel on the bottom of the Marmara is also a navigation problem. A 90-metre wreck in a busy roadstead needs a wreck mark and a depth survey before the anchorage can be treated as normal. The ministry has not said whether the site will be closed to other traffic. Insurers for both ships will open separate files: hull for the Tugberk Imamoglu, collision liability for Alsu, and cargo for the steel that will not reach its receiver.

For the families of the ten, the next official product is a name list and a search log that either finds bodies or explains why it cannot. Uraloglu said on Wednesday that no one had been found alive. That sentence still stands until a later bulletin replaces it. The Marmara does not keep secrets for long in shallow water, but 11 minutes is long enough to put a ship and its watch on the seabed before the first helicopter is overhead.