Milivi was diagnosed with cancer at the age of 2, and a high level of foreign chemicals were found in her blood. Many people have blamed the military's bomb testings in Vieques as the cause for those chemicals to be present in her blood, although that opinion is based on ideas and not specific scientific findings.
When she was 3, she was given 1 month to live, but she survived that, and her cancer seemed to be in remission. However, at the age of 4, cancer reappeared, this time on her brain. She was flown to the United States by her parents, in hopes that treatment would help her.
In the United States, she had to fight other infections, and after the last one, the doctors told her parents that her body would not resist another infection treatment, so she returned to Puerto Rico with her family, where she passed away on the morning of November 17, 2002.
Milivi has a camp named after her in Vieques, Camp Milivi.