What happens when an ulcer bursts in the stomach can you die?

For -burst- stomach ulcers without medical treatment, yes. When an ulcer bursts, blood may enter the stomach, causing blood loss, or stomach contents may enter the abdominal cavity causing sepsis. The ulcer may also break through to other organs, or be a sign of cancer.

If the ulcer bursts, seek immediate medical attention.

However, most stomach ulcers are just painful, and don't burst.