On April 15th...
1865 – Abraham Lincoln dies after being shot the previous evening by actor John Wilkes Booth.
1912 – The British passenger liner RMS Titanic sinks in the North Atlantic at 2:20 a.m., two hours and forty minutes after hitting an iceberg. Only 710 of 2,227 passengers and crew on board survive.
1986 – The United States launches Operation El Dorado Canyon, its bombing raids against Libyan targets in response to a bombing in West Germany that killed two U.S. servicemen.
1989 – Hillsborough disaster: A human crush occurs at Hillsborough Stadium, home of Sheffield Wednesday, in the FA Cup Semi-final, resulting in the deaths of 96 Liverpool fans.
2013 – Two bombs explode near the finish line at the Boston Marathon in Boston, Massachusetts, killing 3 people and injuring 264 others.
http://en.wikipedia.org/wiki/April_15