Video: 'Minute by Minute: The Eruption of Mount St. Helens' (Mar. 27, 1980, at 0:45)

(Thursday, March 27, 1980, 12:36 p.m. PST) — Mount St. Helens, a 9,677-foot volcano in the Cascade Range of southwest Washington that has been dormant for 123 years, spewed forth clouds of steam and puffs of ash today in what scientists called the first stages of an eruption.

This followed nearly two weeks of rumbling earthquakes that have severely shaken the mountain and the surrounding countryside.

No injuries or major property damage were reported, but more than 400 loggers, forest rangers and other residents of the sparsely populated mountain, as well as the village of Spirit Lake at the base of the north slope, were evacuated as a precaution.