Hanford Nuclear ReservationFeb. 23, 1941: Physicist Glenn Seaborg discovers the 94th element, plutonium. The man-made element becomes a building block for nuclear fission.

Feb. 23, 1943: The forced eviction of 1,500 residents in the towns of Hanford and Richland in Washington state clears the way for construction of the Hanford Nuclear Reservation (at right), source of the plutonium for the world’s first atomic bombs. The "Tri-Cities" of Pasco, Kennewick and Richland experience astronomical growth. They experience a second boom in the 1990s, as cleanup workers flood in to the highly contaminated site.

Feb. 23, 1999: The deadliest Alpine avalanche in four decades kills 31 people as a wall of snow travelling at over 200 mph buries the village of Galtur, Austria.

Photo: U.S. Department of Energy/AP

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