Four days after emergency surgery to remove a pool of clotted blood from the surface of his brain, Prison Fellowship founder, author, and radio commentator Chuck Colson was in critical condition at a Washington, D.C., area hospital.

Colson was speaking at a Wilberforce Weekend Conference sponsored by the Chuck Colson Center for Christian Worldview in northern Virginia on Friday when his speech became garbled and he had to sit down, according to witnesses at the event. He was taken by helicopter to a nearby hospital, where he underwent evaluation and then surgery early Saturday.