Justice Department Investigating Whether Airlines Work Together to Keep Prices High

The Justice Department is looking into whether airlines are cooperating to deliberately “work at a slower pace” in order to keep airline prices high, the Associated Press reports on Wednesday.

A department spokesperson confirmed the investigation but declined to list which airlines were subject to the probe. The potential “unlawful coordination” orchestrated by major airlines comes amid questions of why airline ticket prices have remained high despite plummeting oil prices and more fuel efficient aircrafts.

Following news of the probe on Wednesday, all U.S. airline stock prices took a dive.