On shipyard De Eendracht (The Unity) at Kattenburg the slave ship Leusden was built in 1719. In total 6.564 African slaves were transported with this ship, in 10 travels from Africa to the Americas. Almost a quarter of all the enslaved didn't survive the crossing. On January 1, 1738 the ship sank in Surinam. Due to bad weather they arrived at the wrong river mouth, the Marowijne River in stead of the Surinam River, the route to Paramaribo. The waters were shallow and the ship ran aground. All enslaved Africans were sent down to the hold, when the ship started taking water. The hatchways were batten down by the crew because they were afraid to be subdued. The ship sank and 664 people lost their lives. It's the deadliest and most horrifying shipwreck in Dutch history. In 2011, Leo Balai did extensive scientific research and wrote a book about the Dutch maritime history of slavery: The Slave Ship Leusden.