April 18, 1906 – An early morning earthquake rocks San Francisco causing the deaths of over 4,000 people and destruction of 10,000 acres of property.
April 19, 1775 – It was dawn and 70 armed militiamen stood face to face with a British advance guard unit on Lexington Green when an unordered shot from the British became “the shot heard round the world” and the American Revolution began. Eight Americans died and ten were wounded in the melee that followed.
April 20, 1999 – Two students armed with guns and explosives carried out an attack at Columbine High School in Littleton, Colorado, killing 12 classmates and a teacher and leaving 20 people wounded before killing themselves.
April 22, 1970 – An estimated 20 million people turn out for locally-organized environmental educational events promoted by Wisconsin Senator Gaylord Nelson. Nelson was trying to call attention to the inaction of Congress on environmental issues and inaugurated the first “Earth Day”.