Original sentence: The Derry Battalion became the Provisional IRA Derry Brigade in 1972 after a rapid increase in membership following Bloody Sunday when the British Army's 1st Battalion, Parachute Regiment killed 13 unarmed demonstrators at a civil rights march.Tyrone in particular had a large IRA presence with three Brigades formed in the county, the West, Mid and East Tyrone Brigades
Edited sentence: The Derry Battalion became the Provisional IRA Derry Brigade in 1972 after a rapid increase in membership following Bloody Sunday when 1 PARA killed 13 unarmed demonstrators at a civil rights march.Tyrone in particular had a large I.presence with three Brigades formed in the county, the West, Mid and notorious East Tyrone Brigades