Transcript for Feds Investigates Increased Airfares After Amtrak Crash

An angry bus passenger. Sara has a story about angry airline passengers. The fed wants to know some of the big airlines raised their fares. ABC's Mary Bruce has the story from New York's Laguardia airport. Good morning, Mary. Reporter: Hey, Sara, good morning. The cost of flights at this airport allegedly skyrocketed after that train crash and now some are accusing the airlines are purposely raising prices on desperate stranded travelers. This morning, five major airlines under investigation after complaints of unfair sky-high prices. Authorities are questioning whether they took advantage of a horrific deadly train crash to jack up fares. After this train derailed in may in Philadelphia the popular northeast corridor shut down for days. Leaving passengers stranded with little option but to look to the skies. Reported air fares of $500 doubling. One politician even complaining of a $2300 ticket. Did they gouge prices so high and take advantage of a situation. Reporter: The transportation department wants answer. Demanding information. This investigation coming just weeks after a justice department probe into several U.S. Airlines for possibly colluding on prices. The head of one airline is pushing back on the current investigation saying unit ed airlines did nothing wrong. S no. Reporter: He said passengers ended up buying last-minute tickets which usually come at a steeper price. What we saw certainly a surge in demand for tickets and the only available inventory was the last-minute business inventory. Reporter: Now conclusions have been made. Travelsers flock to the airlines. We have reached to the other airlines involved and southwest, jetblue and American tell us they plan to fully cooperate with the investigation. Mary, thank you. Let's check the weather now, and you can tell it's warm when

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