Terry suffered a heart attack at the age of 30, on August 13, 1997, and he died in the hospital five days later, on August 18, 1997. He was a law student at Portland’s Northwestern School of Law at Lewis & Clark College at the time. In his honor, his friends later constructed the Terry Riley Bridge in Portland’s Tryon Creek State Natural Area, which stands in his memory.
His obituary can be found here.