As flight cancellations and delays pile up, airlines may not be back on track until Labor Day

It was a tough holiday weekend, as airlines canceled 1,200 flights Friday, another 1,200 Saturday and about 300 and 225 on Sunday and Monday, July 4, respectively. Delayed flights were also in the thousands, with ground stops — all traffic halted — at airports like Denver, Miami, Atlanta, Newark and Minneapolis. And travelers weren't delayed just by airlines and on the tarmac, but at many passenger security checkpoints at U.S. airports.

Overseas, major delays and cancellations occurred at airports like Lisbon, Frankfurt, Dublin and Amsterdam. The situation in Amsterdam was so serious, the Netherlands issued an unprecedented order telling airlines to suspend selling any more tickets between now and the end of July. That almost immediately drove up the price of airfares — which are now sky high. On many trips within Europe, the train is rapidly becoming a very attractive option.

Delays and cancellations are likely to continue, as airlines can't either find workers, or if they do, train new employees fast enough.