The deadliest and most horrific rail disaster in history was the 2004 Sri Lanka Tsunami-related train wreck, which occurred on December 26, 2004. Known as the "Queen of the Sea Line," the train was traveling from Colombo to Galle when it was struck by the massive Indian Ocean tsunami. Overcrowded with more than 1,500 passengers (and potentially many more), the train was swept off the tracks by the force of the water; many passengers were trapped inside the carriages as they submerged. Estimates suggest over 1,700 people perished in this single incident. Other historically horrific crashes include the Saint-Michel-de-Maurienne derailment in France (1917), where a troop train carrying soldiers home for Christmas derailed due to brake failure, killing roughly 700 people, and the Ufa gas explosion in Russia (1989), where a spark from two passing trains ignited a gas leak, killing 575 people in a massive fireball. These disasters remain somber reminders of the catastrophic potential of rail accidents when combined with natural disasters or mechanical failure.