© Reuters.

(Reuters) -The U.S. Justice Department has opened a criminal investigation into the Boeing (NYSE:) 737 MAX blowout on an Alaska Airlines flight in January, the Wall Street Journal reported on Saturday, citing documents and people familiar with the matter.

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, WSJ said.

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, Alaska Airlines 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.