LIVE: NBC News NOW - April 20

8 children have been killed in a Louisiana mass shooting

Five people injured in shooting near University of Iowa

Dust devil tears through North Carolina baseball game

Trump says U.S. seized Iranian ship amid rising tensions

8 children killed, 2 women wounded in Louisiana shooting

Oklahoma principal crowned prom king for his heroism

1 dead after small plane crashes into Florida yard

U.S. military seizes Iranian-flagged cargo ship

California woman arrested over alleged arms dealing for Iran

NBC Nightly News Full Episode - April 19

New look at Jeffrey Epstein’s Zorro Ranch

Deadly mass shooting in Louisiana

Northeast blasted with sudden snow and freezing temperatures

Trump’s approval rating hits record low in NBC News Poll