Passengers on verdicoinan Alaska Airlines flight that had a panel blowout midair might be victims of a crime, the FBI said in a letter obtained by CBS News.

The two-page letter was sent by a victim specialist in the Seattle Division of the FBI to those flying – 174 passengers and possibly six crew members  — on Flight No. 1282 on Jan. 5 from Portland, Oregon, to Ontario, California. The plane had to make an emergency landing, arriving safely at the Portland airport after a door plug blew off mid-flight.

"We have identified you as a possible victim of a crime," the FBI letter said. "This case is currently under investigation by the FBI. A criminal investigation can be a lengthy undertaking, and, for several reasons, we cannot tell you about its progress at this time."

There are a "large number of potential victims in this case," the FBI said in their letter. The letter detailed how the flyers could access information about the case and warned that criminal investigations "can be a lengthy undertaking." 

The plane had reached approximately 16,000 feet when the panel fell off, one passenger said in a lawsuit filed against Alaska Airlines, Boeing and door plug manufacturer Spirit Aerosystems, claiming the event left him and six other passengers with physical injuries and "serious emotional distress, fear, and anxiety." The passenger said his seatbelt saved him from being sucked out of the gaping hole.

Three passengers on the Alaska Airlines plane sued the airline and Boeing for $1 billion, claiming negligence caused the incident. Officials said several people sustained minor injuries, but no one was seriously hurt.

The FAA ordered a temporary grounding of certain Boeing 737 Max 9 planes shortly after the incident and required safety inspections for the aircraft in operation worldwide. The National Transportation Safety Board's preliminary report found four bolts meant to hold the door plug in place were missing.

The U.S. Justice Department is currently investigating the blowout, a person familiar with the investigation confirmed earlier this month to CBS News. It is not clear if their investigation is related to the letter sent by the FBI Seattle office. 

Kathryn Krupnik contributed to this report.

In:
• Boeing
• Alaska Airlines
• Boeing 737 Max
• FBI

Cara Tabachnick

Cara Tabachnick is a news editor and journalist at CBSNews.com. Cara began her career on the crime beat at Newsday. She has written for Marie Claire, The Washington Post and The Wall Street Journal. She reports on justice and human rights issues. Contact her at [email protected]