What are the main events for the story "The Sniper?"

Liam O'Flaherty's "The Sniper" is a classic action and
suspense story set during the Irish Civil War with a surprise ending. A sniper sits on
the rooftop of a building pinned down by an enemy sniper on another rooftop across the
street. When an old woman in the street below threatens to make his presence known to
the enemy, the sniper is forced into action. To protect the secrecy of his presence, he
kills both the old woman and the enemy soldier she attempts to inform. However, in the
time it takes him to shoot these two individuals, the sniper on the rooftop across the
street fires upon him, wounding him the arm. Now the sniper's only chance to survive is
to somehow dispose of the enemy sniper across the street and escape the roof before
morning. However, unbeknownst to the sniper, the identity of the man on the rooftop
across the street complicates the story's resolution.