April Fools Day is 911 Pt 1.

4/1/2001= 91st day of Year. 1st day of April
April= 4th month. 4 planes 9/11.
91st day of year and 2-0-0-1= 1.

Sunday April First Two Thousand One= 1 sentence 36 characters.
1-36= 666

153 to #’s. 13 letters= 166
April Fools Day 2001 was Sunday= 6 letters.
Twin Towers= 166 to #’s. Towers= 6 letters.