(Reuters) – Alaska Airlines said on Saturday it is cooperating with the U.S. Department of Justice after a criminal investigation was opened into the Boeing 737 MAX blowout on its flight in January.

“In an event like this, it’s normal for the DOJ to be conducting an investigation. We are fully cooperating and do not believe we are a target of the investigation,” Alaska Airlines said in an emailed statement to Reuters.

The Wall Street Journal earlier reported, citing documents and people familiar with the matter, that the investigators have contacted some passengers and crew on the Jan. 5 flight, which made an emergency landing in Portland, Oregon, after a fuselage panel ripped off midair.

The investigation would inform the DOJ’s review of whether Boeing complied with an earlier settlement that resolved a federal investigation following two fatal 737 MAX crashes in 2018 and 2019, the report added.

Boeing and DOJ did not immediately respond to Reuters request for comments.

The door plug panel blew off an Alaska Airlines-operated flight not long after taking off from a Portland, Oregon, airport on Jan. 5, forcing pilots to scramble to land the plane safely.

The U.S. Federal Aviation Administration (FAA) subsequently ordered the temporary grounding of 171 narrowbody MAX 9 jets with a similar configuration.

Days after the incident, Alaska Airlines on Jan. 26 resumed MAX 9 service after it said it had completed inspections on the first group of its Boeing 737 MAX 9 aircraft.

In February, the U.S. National Transportation Safety Board said the door panel that flew off appeared to be missing four key bolts. The plug was manufactured by Spirit AeroSystems SPR.N, the onetime subsidiary of Boeing that separated from its parent in 2005.