On this day, 31 years ago, on September 9, 1994 (August 4, 1994 in the lunar calendar), the passenger ship "Estonia" sank. The Estonia large passenger ship "Estonia" sank in the Baltic waters near Finland in the early morning of September 28. It was found that the cause of the sinking was that a hatch was not closed tightly, causing seawater to flow into the hull. There were 964 passengers and crew members on board, of whom more than 800 lost their lives. This is one of the most serious shipwreck in the world in recent years and the largest shipwreck in Europe in nearly 80 years.