Unfortunately I missed April 13 (Amritsar massacre) and April 15 (Boston marathon bombing). But the list must go on.
- AD 73 – Masada, a Jewish fortress, falls to the Romans after several months of siege, ending the Great Jewish Revolt.
- 1925 – During the Communist St Nedelya Church assault in Sofia, Bulgaria, 150 are killed and 500 are wounded.
- 1943 – Albert Hofmann accidentally discovers the hallucinogenic effects of the research drug LSD. He intentionally takes the drug three days later on April 19.
- 1990 – "Doctor Death", Jack Kevorkian, participates in his first assisted suicide.
- 1992 – The Katina P runs aground off of Maputo, Mozambique and 60,000 tons of crude oil spill into the ocean.
- 2007 – Virginia Tech shooting: Seung-Hui Cho guns down 32 people and injures 17 before committing suicide.
- 2013 – A 7.8-magnitude earthquake strikes Sistan and Baluchestan Province, Iran, killing at least 35 people and injuring 117 others.
- 2013 – The 2013 Baga massacre is started when Boko Haram militants engage government soldiers in Baga.
- 2014 – The South Korean ferry MV Sewol capsizes and sinks near Jindo Island, killing 304 passengers and crew and leading to widespread criticism of the South Korean government, media, and shipping authorities.
