South African and American researchers are planning to hold a memorial in Cape Town for slaves who died when the Portuguese ship that was carrying them into bondage sank while sailing to Brazil in 1794.

The memorial is to take place Tuesday on a Cape Town beach near where the Sao Jose sank.

Iziko Museums, a group based in Cape Town, says more than 400 African slaves were on board the vessel when it sank. About half the people on the ship died.

Artifacts from the ship were recovered this year. Iziko Museums worked with the Smithsonian's National Museum of African American History and Culture on the project.