Kate Chopin raises many different issues in her short story Desiree's Baby. Racial prejudice, isolation, violence, the concept of love, and identity. Within these themes, one can suggest that many different things could have led to the death of Desiree.
First, I need to suggest that Desiree's death is one which is left in question. Chopin only states that Desiree is never seen again after leaving L'Abri. Some may believe that this suggests that Desiree does die. Others may believe that Desiree simply disappeared.
As for the suggestion that Desiree may have died based upon the racial injustice she faced at the hand of Armand, one can certainly justify this. Given that Armand exiles her and their child from their home, based solely upon the fact that their child "is cursed with the brand of slavery," one could say that she died of racial injustice.Other readers may see things a little differently.
Chopin's texts dealt with many different things (love being one). In other texts of Chopin's, like Story of an Hour, love (or lack of love) is a killer. Therefore, some may believe that Desiree simply died of a broken heart. She love Armand with all of her heart, he accepted her for being an "unknown," and refused to look down upon her. Based upon this, some may say that Armand's exile of Desiree broke her heart.