The 14 Russian sailors killed in last week’s nuclear submarine fire may have prevented a “planetary catastrophe,” a high-ranking officer has reportedly said at their funeral ceremony this weekend.

The sailors were killed on July 1 when a fire broke out as their deep-water research submarine was surveying the seafloor near the Arctic, the Russian Defense Ministry has said. President Vladimir Putin disclosed for the first time on Thursday that the secret military submarine was nuclear-powered, prompting the defense minister to assure him its reactor had been safely contained.