- Born in New Brunswick, he resided in Kendall Park most of his life
- He graduated from South Brunswick High School in 1982, where he was active as a member of the Outdoor Club, a member of the junior varsity football team, and a member of the band
- Cpl. Estler was a member of Troop 90 Boy Scouts sponsored by the Community Presbyterian Church of the Sand Hills, Kendall Park, and in 1981, he was the first member of the church to receive his Eagle award
- He served as an assistant scoutmaster
- LCpl Sean F. Estler died on October 23rd, 1983 in Beirut, Lebanon from injuries of a suicide truck bomb attack on the Marine Barracks