Complex sentence: On August 25,2011, the Ultimate Indoor Football League announced that the Explosion would leave the SIFL and join their league; the change would reunite Erie with Andrew Haines, who founded the city's previous indoor football team, the Erie Freeze.
Split into simpler sentences: On August 25,2011, it was announced the Explosion would be leaving the SIFL to join the Ultimate Indoor Football League. The change reunites Erie with Andrew Haines, who founded the city's previous indoor football team, the Erie Freeze.