UV light does not just create repairable dimers in DNA bases, it can and does rip DNA apart. Enough exposure would cause more than enough irreparable damage to kill the cell and 99% of the cell being destroyed is certainly not salvageable.
The Delta flight is cheaper. But check a bag at a cost of $25 for the first checked bag each way on Delta, and your total fare climbs to $256 -- more than the cost of the Southwest flight, which includes free first and second checked bags. Add a second checked bag for $35 each way on the Delta flight, and you'll pay a whopping $326.
Delta says: Basic Card Members with a Gold Delta, Platinum Delta, or Delta Reserve SkyMiles Credit Card from American Express and up to 8 people traveling on the same itinerary, may check their first bag for free on all Delta and Delta Connection flights.