The Justice Department is opening an investigation into the Alaska Airlines incident in which a door panel exploded in mid-air, WSJ reports.

The Ministry of Justice has launched a criminal investigation into the fact Alaska Airlines incident where a door panel exploded in mid-air two months ago, The Wall Street Journal reports this. Saturday.

The newspaper, citing documents and people familiar with the matter, said investigators had contacted passengers, pilots and flight attendants on Jan. 5 Flight 1282, bound for Ontario, California, from Portland, Oregon, where part of the plane broke off in mid-air, causing the crew made an emergency landing.

The investigation will help the Justice Department examine whether Boeing complied with a previous agreement in the federal investigation into two fatal 737 Max crashes in 2018 and 2019, the Journal reported.

“In this case, it is normal for the Department of Justice to investigate,” an Alaska Airlines spokesman said. “We are cooperating fully and do not believe we are the target of an investigation.”

The Justice Department declined to comment. Boeing did not immediately respond to CNBC’s request for comment.

Boeing 737 Max 9 aircraft flying over Alaska have resumed scheduled flights after being grounded for inspections. Alaska and United Airlines, the two U.S. carriers that operate the Max 9, canceled thousands of flights in January following the incident.

Three passengers are suing Boeing and Alaska Airlines for $1 billion in damages, accusing Boeing and Alaska Airlines of negligence for allegedly ignoring warning signs.

Alaska Airlines previously estimated that a week-long grounding of Boeing 737 Max 9 flights would cost the carrier $150 million.

— Read the original WSJ story. Here.

— CNBC’s Rebecca Picciotto contributed reporting.