JUST IN: Alaska Airlines Boeing 737 appeared to have bolts missing when panel blew out mid-flight in January

The new information was brought to light by the National Transportation Safety Board, which had been investigating the cause of the malfunction.

According to CNBC, the NTSB discovered that bolts were nowhere to be found on sections of the door plug, which covered an unused emergency exit. The panel blew off Alaska Airlines Flight 1282 while it was en route from Portland, Oregon to Ontario, California on January 5.

The flight was forced to make an emergency landing after the incident caused depressurization of the cabin.

"Overall, the observed damage patterns and absence of contact damage or deformation around holes associated with the vertical movement arrestor bolts and upper guide track bolts in the upper guide fittings, hinge fittings, and recovered aft lower hinge guide fitting indicate that the four bolts that prevent upward movement of the MED plug were missing before the MED [mid exit door] plug moved upward off the stop pads," the report stated, per CNN.

In a statement prior to the report's release, Beoing CEO Dave Calhoun said that "whatever final conclusions are reached, Boeing is accountable for what happened," adding, "An event like this must not happen on an airplane that leaves our factory. We simply must do better for our customers and their passengers."

This is a developing story. Check back for updates.