Bad News Boeing.

Now, the airplane manufacturer has more to worry about than just its failed 737 Max jet.

Federal air-safety officials are investigating the Boeing 737 model after the “skin” of a Southwest Airlines Boeing 737 cracked Monday night during a flight from Las Vegas to Boise, Idaho.

The 12-inch break in the outer aluminum surface caused the craft to lose cabin pressure and drop 20,000 feet, according to the Wall Street Journal. No one was injured.

Fatigue cracks are common in older planes, which make up Southwest’s fleet.

The airline had ordered 737 Max planes from Boeing, but regulators grounded the model after two crashes — one in October 2018, the other in March 2019 — killed 346 people. Regulators also have found trash in Max fuel tanks.