MS Estonia (Estonia) – The MS Estonia sank in heavy seas on 28 September 1994. An investigation claimed that the failure of the bow visor door allowed water from the Baltic Sea to enter the ship. The accident claimed 852 lives. Only 137 survived.
The Deadliest Maritime Disaster - Sinking of the MS Estonia in 1994 (en route from Tallinn, Estonia to Stockholm, Sweden) 20 years ago from September 27, 2014 - I have friends who lost someone in that disaster and I also met a survivor of that disaster (47 minutes)