A Delaware family's Caribbean vacation turned into a nightmare when they were reportedly poisoned by a toxic pesticide while visiting the U.S. Virgin Islands. The two teenage sons are unconscious in a Philadelphia hospital, while their dad is conscious in a Delaware hospital but unable to move, according to CNN and The News Journal in Delaware.

On March 20, when paramedics arrived at the reportedly $550-to-$1200-a-night villa the family was renting at the Sirenusa resort on St. John, they found Stephen Esmond unconscious, and his wife, Theresa Devine, and their two sons having seizures. They were rushed to a local hospital then airlifted to the U.S. three days later.

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Subsequent testing of their villa by the Environmental Protection Agency (EPA) turned up the pesticide methyl bromide, per an EPA spokesperson. This pesticide is so toxic it has been banned in the U.S. except in limited agricultural settings. The News Journal reports that Terminix had fumigated the condo below the Esmond's with the odorless gas on March 18.

Methyl bromide can cause nervous system and respiratory system damage, according to the EPA, which is why it's illegal to use indoors. As Judith A. Enck, EPA Regional Administrator, wrote in a statement: “Pesticides can be very toxic and it is critically important that they be applied properly and used only as approved by EPA.” The U.S. Department of Justice has opened a criminal investigation into the incident.

Meanwhile, Devine, who is a dentist, has been released from the hospital. But her husband—the head of a private middle school in Delaware—and their high-school-age sons are still critically ill, fighting to regain their health.

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