5 Airlines Probed for Allegedly Raising Fares After Amtrak Crash

— -- Five airlines are being investigated by the federal government over allegations that they raised airfares in the Northeast as desperate travelers flocked their way after the deadly May 12 Amtrak crash in Philadelphia.

"Obviously when service goes down on something like an Amtrak line that carries so many thousands and millions of people on an annual basis and it's out of service for a number of days, you know the airlines are going to pick up business," Transportation Secretary Anthony Foxx said today.

"The question is beyond normal practices, did they gouge prices so high and take advantage of a situation when the public was obviously out of service with the Northeast corridor," he added.

The department said its investigation involves Delta, American, United, Southwest and JetBlue, and seeks to find out whether the airlines had violated federal regulations.

"We do feel that there's a sufficient amount of information and evidence to be an investigation and to learn more," Foxx said.

United Airlines CEO Jeff Smisek told ABC News today that travelers at that time had faced last-minute airfares, which are generally higher than flights booked in advance.

"We would never take advantage of an opportunity like that, if you viewed it as an opportunity," Smisek said.

In a statement, American Airlines said "in response to the Amtrak derailment, we added capacity and our fare structure remained the same. We are cooperating with the [Department of Transportation] and are confident that there will be no finding of wrongdoing by American."

Delta said that after the crash, it had actually reduced shuttle prices, and JetBlue and Southwest said they were working with the government, according to the Associated Press.

Many commuters were stranded for nearly a week before Amtrak service returned to normal on May 18 after the derailment of Northeast Regional train No. 188. Eight were killed in the Philadelphia crash and more than 200 were injured, authorities said.

In May, Sen. Christopher Murphy of Connecticut helped spark the federal probe after he wrote a letter to the Obama administration, complaining of increased fares.

"The idea that any business would seek to take advantage of stranded rail passengers in the wake of such a tragic event is unacceptable," Foxx said in a statement. "This department takes all allegations of airline price-gouging seriously."