Pictured: The hospital ship in question. In a dark coincidence, the ship’s name was Armenia.

Quoting David Williams’s In Titanic’s Shadow: The World’s Worst Merchant Ship Disasters:

Having earlier called at Sevastopol, the Armenia arrived at Yalta bound for Tuapse on 6 November 1941 on the first of this phase of mercy runs. There she embarked a huge number of people, variously put at from 5,500 to 10,000 but believed to have been actually of the order of 7,000. Crammed aboard her were wounded soldiers, civilian evacuees, the staff of the Central Black Sea navy hospital, along with the staff and patients from twenty-three other military and civil hospitals in the region. The order from Naval Command had been to take all medical personnel, injured and ill people from all of the hospitals in and around besieged Sevastopol.

One of the mysterious aspects of the Armenia case, which was to have a major influence on what was to transpire, was why the authorities insisted so many vulnerable people should be embarked on the Armenia alone when there were other hospital ships in the port. Given the desperate circumstances, with Odessa already fallen, Rostov close to being overrun and the whole of the Crimea threatened, every available ship was involved in getting the casualties out and, to bolster the defences, reinforcements in — but other hospital ships did have spare capacity.

When the Armenia was ready to sail, Russian Naval Command instructed her master to delay his departure until 19.00 hours at the earliest, when light was falling, or until escorts became available. For a reason that no one now can explain, Captain Plaushevsky ignored these orders. He did wait at Yalta through the night but the following morning, 7 November 1941, at 08.00 hours, he put to sea, bound for Tuapse in broad daylight and without a proper escort.

Less than four hours later, reports say at 11.25 hours, the Armenia was spotted off the coast near Gurzuf by Heinkel He 111H bombers of Kampfgeschwader 28, which immediately attacked. The planes had been armed for attacks on shipping and, besides dropping their bombs, they also carried torpedoes, which they unleashed at the Armenia. One hit the helpless ship at her forward end. With her bows and forepart blasted away completely, she sank almost immediately. A survivor, one of only eight picked up later by a naval escort vessel, timed the sinking at 11.29 hours, only four minutes after the assault had started. In such a brief interval, there was no opportunity to organise anything even remotely like a proper evacuation of the ship.

The [Axis] pilots had no excuse for their actions. They certainly could not have been mistaken about the Armenia’s function, for standing out brightly in the morning sunshine, her white hull and prominent red crosses would have been clearly seen: they chose deliberately to disregard the markings. An eyewitness who had watched the tragedy unfold from the shore later recalled:

Hardly had the boat reached the open sea, when a group of [Axis] planes attacked it. It goes without saying that the [Axis] pilots could see the big red crosses on the ship. Nevertheless, they started bombing the vessel. We could hear both bomb explosions and people’s screaming.

Maybe Captain Plaushevsky had taken his chances that fateful day because he felt sure the [Axis] would not attack a ship operating under the protection of the Red Cross, but sadly his judgement failed him.

The catastrophic loss of the Armenia was then, and remains to this day, the worst ever involving a Russian ship. For just over three years it was the world’s worst maritime disaster with an official figure of 5,000 casualties, although it is widely accepted that the actual number of dead was nearer to 7,000.

(Emphasis added.)