Editor's note: Since the publication of this story, reports have emerged that the 13 Ukrainians were captured, not killed. On Saturday, the Ukrainian Border Patrol Agency said that it had "received hope that all of Zmiiny's defenders are alive." Russian state-controlled media reported the island's defenders had surrendered. The Ukrainians said they sent a ship to investigate the island on Saturday but added it was captured by the Russians. Monday, the Ukrainian Navy announced that it was "very happy to learn that our brothers are alive and well" and described them as having been captured by the Russians.
In the early hours of Russia's invasion of Ukraine, defenders of a small island in the Black Sea received a transmission from a Russian warship -- consider your loved ones and surrender.
The 13 Ukrainian border guards stood fast, held the island for about 12 hours, and delivered a final, defiant message to the Russians: "go f--k yourself."
According to Ukrainian government posts, the border guards were stationed on the tiny but strategic Snake Island, located about 30 miles off the southern tip of the Ukrainian mainland, near the Romanian border. It's less than a square mile in size but vital to the country's territorial claims.
Several hours after the first call to surrender came over the radio, Russian warships opened fire, the Ukrainian government said. The flagship of Russia's Black Sea fleet -- the missile cruiser Moskva and the patrol ship Vasily Bykov -- were reported in the area, according to the Ukrainians.
Yet, despite hours of bombardment, the defenders held on. An hour later, the Ukrainian government said that the island was still under its control, despite attacks from the air and sea.
At some point in the attack, the Russians offered Snake Island's defenders one last chance.
According to an audio recording, initially posted to Telegram by an adviser to Ukraine's interior minister, the Russian warship radioed: "I am a Russian warship, I repeat: I suggest you lay down your arms and surrender otherwise you will be bombed."
The recording goes silent, and the defenders are heard saying, "This is it." Then came their reply.
"Russian warship - go f--k yourself."
The recording went viral on the internet and was posted on the Ukrainian news outlet "Ukrayinska Pravda", as well as many Western media outlets. The Washington Post reported that it had confirmed the recording's authenticity with a Ukrainian official.
Late on Thursday, Ukrainian officials said that the island's infrastructure was destroyed and all contact with the defenders was lost. Ukrainian President Volodymyr Zelensky, in an update after the first day of fighting, said all of the island's defenders were killed. He added that he was conferring the title "Hero of Ukraine" -- the nation's highest honor -- on all the defenders of the island.
In all, Zelensky said the defenders were among the at least 137 Ukrainians who were killed in the first day's fighting.
Although tiny, the island's defense at all costs underscores its strategic importance to Ukraine. The Atlantic Council think tank called the spit of land "key to Ukraine's maritime territorial claims" in the Black Sea in an article last year. Zelensky chose to highlight the island's importance by hosting an interview with Ukrainian media in advance of a summit over the annexation of Crimea last year.
"This small island, like any other of our territory, is Ukrainian land and we will defend it with all our might," Zelensky told reporters then.
Now, "despite its acquisition through illegal annexation, Russia could declare that it is entitled to the island's maritime claims," security analyst Michael van Ginkel wrote in a message to Military.com.
Controlling the island and its sea lanes "allows Russia to regulate traffic between Ukrainian Black Sea ports like Odessa/Kherson and international markets," van Ginkel noted.
"Likewise, it is strategically placed to regulate trade that transits the Danube River, which is a major EU transport corridor for commerce," he added.
The island's siege and capture also underscores the uncontested naval presence that Russia has in the Black Sea. The ship that reportedly took part in the attack -- the Moskva -- is a massive, 11,000-ton cruiser that was launched by the Soviet Union in the 1980s to take on U.S. aircraft carriers by overwhelming them with volleys of high-speed cruise missiles.
The U.S. Navy has deployed 14 ships, including a carrier strike group, to the European area of operations -- a number of ships that has not been seen since the Cold War. However, a spokeswoman for the branch told Military.com on Thursday that none of them is in the Black Sea.
-- Konstantin Toropin can be reached at email@example.com. Follow him on Twitter @ktoropin.