The pilots went on "strike" 2008 but they weren't union to my knowledge. The FAA grounded some of their planes a couple times in 2009. Engine and cargo restraint issues. The Post Office cancelled their mail contract in Nov 09 which did them in. One of their planes had a cockpit fire on taxi out that burned the nose off to the meat hatch door. The company was saying it was repairable - you be the judge.
Photo of Douglas DC-3C N136FS - Aviation Safety Network
I'll be the first to say it, "The front fell off."