On this day: April 16

POSTED: 09:35 AM PDT Apr 15, 2013    UPDATED: 11:00 PM PDT Apr 15, 2014 
Virginia Tech shootings sign

LSD's creator drops acid (accidentally) for the first time, Martin Luther King writes his "Letter from Birmingham Jail," The Rolling Stones release their debut album, and tragedy strikes Virginia Tech, all on this day.