1953

Francis H.C. Crick announced that he and fellow scientist James D. Watson had discovered the double-helix structure of DNA.

1993

A gunbattle erupted at a religious compound near Waco, Texas, when Bureau of Alcohol, Tobacco and Firearms agents tried to arrest Branch Davidian leader David Koresh for stockpiling illegal weapons; four agents and six Davidians were killed as a 51-day standoff began.

2013

Benedict XVI became the first pope in 600 years to resign, ending an eight-year pontificate.

2023

A passenger train collided head-on with a freight train more than 200 miles north of Athens, Greece, killing 57 people in that country’s deadliest rail disaster.