More than two million Americans visit the Dominican Republic every year, making up about a third of the country’s tourists. Six have died in the last year during their visits. Because of the seeming similarities among their deaths, their family members have suggested that they are connected and have raised suspicions about the resorts where they died. Here’s what we know, and don’t know, about the circumstances.

Who has died, and how?

Yvette Monique Sport, 51, died in June 2018 of a heart attack. Her sister, Felecia Nieves, has said that Ms. Sport had a drink from the minibar in her room at a Bahia Príncipe resort, one of a number on the island, then went to sleep and never woke up.

In July 2018, David Harrison, 45, died at the Hard Rock Hotel & Casino Punta Cana. Mr. Harrison died of a heart attack and The Washington Post reported that his death certificate also listed “pulmonary edema, an accumulation of fluid in the lungs that can cause respiratory failure, and atherosclerosis” as causes of death. He and his wife were in the Dominican Republic for their wedding anniversary with their son.

In April of this year, Robert Wallace became sick at the Hard Rock Hotel & Casino Punta Cana, where he was attending a wedding and died. The 67 year old’s family said that he became ill after drinking scotch from the minibar in the hotel.