A fourth U.S. tourist has died in the Dominican Republic after family members say he became sick almost immediately after having a drink from his minibar at a resort.

According to family members, Robert Bell Wallace, of California, was in good health before the trip.

Family members say Wallace was there for his stepson's wedding.

Three other Americans have died at all-inclusive resorts in the Dominican Republic in the past month.

Autopsy results show Miranda Schaup-Werner, of Pennsylvania, died of a heart attack in her room in late May.

A couple from Maryland, Nathaniel Edward Holmes and Cynthia Day, had internal bleeding of the pancreas and liquid in the lungs.

The FBI is assisting with toxicology tests.