Fogonazos blog has a short feature on David A. Johnston, the volcanologist who was first to report the Mount St. Helens volcano eruption in 1980 before being swept away by the blast:
Johnston was manning an observation post about 10 km (6 miles) from the volcano Mount St. Helens on the morning of May 18, 1980. He was the first to report the eruption, transmitting the famous message "Vancouver! Vancouver! This is it!" before being swept away by the lateral blast created by the collapse of the mountain's north face. His body was never recovered.
Link (with an awesome video clip of the eruption) - Thanks aberron!