Milestones

DIED

Chris Kelly, 34, half of the hip-hop duo Kris Kross, who rode their backward clothes and 1992 single “Jump” (eight weeks atop the Billboard Hot 100) to multiplatinum crossover success.

UNVEILED

By University of Texas law student Cody Wilson, the Liberator, a gun he created on a home 3-D printer. It can be made with no metal pieces, making it virtually invisible to standard metal detectors.

WON

The Kentucky Derby, by Orb, who came from behind to win at Churchill Downs by 2½ lengths. It was the first Derby win for Hall of Fame trainer Shug McGaughey in his more than 30-year career.

DIED

Christian de Duve, 95, Belgian biochemist, whose work with differential centrifugation helped unlock the mysteries of the cell, earning him a share of the Nobel Prize in Medicine in 1974.

PARDONED

By the government of Ireland, nearly 5,000 men who deserted the armed forces of their neutral country to fight the Nazis during World War II. Only about 100 of the Irish war veterans are still alive.

DIED

Jeff Hanneman, 49, a founding guitarist of Slayer, one of the major thrash-metal bands founded in the ’80s, along with Metallica and Megadeth, whose dark lyrics and furious play won legions of fans.