Katherine Tyson was known to many in the Mount Vernon community as a committed environmental activist, a leader in the Unitarian Universalist Church and a dedicated student at Boston University, where she recently graduated. But her life was cut short in a car crash last week in Colorado as she was returning from the Unitarian Universalist annual General Assembly in Salt Lake City. She was 21.

"We are completely devastated, as are our friends at Mount Vernon Unitarian Church and the many people who knew and loved our daughter," said parents Karen and Herb Tyson in a written statement.

A native of Mount Vernon, she was a 2006 graduate of Thomas Jefferson High School for Science and Technology and a National Merit Scholar. In May, she graduated cum laude from Boston University, where she studied mathematics and statistics. She planned to begin graduate studies for a doctorate in biostatistics in September. She was active in the Mount Vernon Unitarian Church, where she served on church committees, sang in the choir and frequently played the piano for worship services.

Family members described her as interested in photography, music, baking, writing, computers and running. She was a Girl Scout for 13 years and held a second-degree black belt in karate.