Event:
Tropical Butterfly Garden at Cleveland Metroparks Zoo opens
More Notable Events on May 18:
1980 Mount St. Helens blows its top in Washington State, 60 die
1953 Jacqueline Cochran is 1st woman to break the sound barrier
1951 U.N. moves headquarters to New York City
1927 Grauman's Chinese Theater opens in Hollywood California
1804 Napoleon Bonaparte proclaimed Emperor of France
