General fact: 70 is the number of years of marriage until the platinum wedding anniversary.
Mathematical fact: 70 is the smallest weird number.
Trivia: 70 is the distance (meter) from archer to targets in Olympic Archery.
Historical date: March 10th is the day in 1945 that the U.S. Army Air Force firebombs Tokyo, and the resulting firestorm kills more than 100,000 people, mostly civilians.