He co-founded the successful mobile payments company Square, but Tristan O'Tierney's story came to a tragic ending: He died Feb. 23 at age 35. Details of his death are scarce, but his mother tells the San Francisco Chronicle "it was in relation to his addiction." She says he couldn't breathe, arrived at a hospital, "and they couldn’t revive him." She adds, to Bloomberg, that a doctor told her her son had suffered kidney failure and went into cardiac arrest. In addition to her, he is survived by his father, sister, girlfriend, and 3-year-old daughter. His family is still awaiting an official cause of death.
O'Tierney's mother says he had been battling addiction for three years; the Chronicle notes that he was open about those struggles on social media. He was in a three-month rehabilitation program in Ocala, Fla., the city where he died. Born in Alaska, O'Tierney grew up in multiple states and eventually settled in New York before moving to California's Bay Area in 2005. He worked at tech companies including Yahoo and Apple. He left Square in 2013. "Tristan was part of Square's founding story and we are deeply saddened by his passing. Our thoughts are with his family and friends," a company rep tells Business Insider, which rounds up remembrances of O'Tierney on social media. (A founder of Vine died in December at age 35.)