Conversation so far:
What happened to cause the accident of Casey Jones' death?
Who was involved in the accident of Casey Jones' death?
Casey Jones's train collided with the caboose of a stalled freight train near Vaughan, Mississippi.
Did Engineer Casey Jones die?
Casey Jones was killed on April 30, 1900, when his train collided with the caboose of a stalled freight train near Vaughan, Mississippi.

Question: How bad was the accident?
Self-contained rewrite: How bad was Casey Jones' train accident?