Southwest flight from Orlando to Pittsburgh diverts due to low fuel emergency

Greater Pitt was closed due to airshow in progress. The Southwest flight that flew nonstop — to West Mifflin
http://www.post-gazette.com/local/region/2017/05/16/Southwest-flight-pittsburgh-allegheny-airport-west-mifflin/stories/201705160051

After reading the rest of the story, it's like a re-run of the Allegiant incident last year.

I would hate to be in the shoes of the Southwest Dispatcher on 3316.

I'm thinking the captain did exactly what you're supposed to do when at low fuel status; no what the reason for the situation.