Mount St. HelensMarch 27, 1964: A massive earthquake hits Prince William Sound, Alaska on the Good Friday religious holiday. The magnitude 9.2 quake and resulting tsunamis killed over 100 people as far away as Crescent City, California. There was heavy damage in Anchorage, Alaska's largest city, and the port city of Valdez was partly destroyed. Several years later, Valdez was moved to higher ground, several miles away from its former location.

March 27, 1980: After 127 years of relative quiet, the Mount St. Helens volcano (at right) in southwestern Washington State rumbles and emits loud explosions, forming a small crater near the summit. The volcano violently erupts in May.

March 27, 1980: The Norwegian North Sea drilling rig Alexander Kielland capsizes, killing 123 of the 212 people aboard. The Kielland had been decommissioned for drilling but was serving as a "floatel" to lodge workers from nearby rigs.

Photo: Lawerence Leonard Gilbert/Flickr

This feature is compiled by Peter Dykstra, an MNN contributor and publisher of Environmental Health News and The Daily Climate.