72-hour sale: Southwest fares fall below $100 round-trip October 9, 2017 by quixnet 72-hour sale: Southwest fares fall below $100 round-tripCNBC Wanna get away, Michigan? Southwest fares fall below $100 as part of 72-hour saleDetroit Free Press Southwest Airlines launches three-day sale with one-way fares as low as $48Orlando Sentinel Full coverage