The first man died in April 2014. Another died later that month. Then on July 18 of that year, a woman was rushed to a hospital where she was told she was lucky to be alive.

They all went to the same Little Rock, Ark., surgery center for a colonoscopy, among the safest procedures a patient can have. And each stopped breathing soon afterward, court records say, sustaining the same type of brain damage seen in a drowning victim. Read More