The U.S. government has opened an investigation into snow removal at New York’s John F. Kennedy International Airport following a storm earlier this month that snarled scores of flights.

The Federal Aviation Administration is probing the Port Authority of New York and New Jersey’s actions during the storm Jan. 4-5, the agency said Tuesday in an emailed statement.

The investigation will determine “if the Port Authority was in compliance with federal aviation regulations which require prompt and timely removal of snow from all aircraft movement areas,” the agency said.

Kennedy endured days of flight cancellations that stranded passengers and created gridlock. A burst pipe in bitter cold temperatures on Jan. 7, added to the problems. Former U.S. Transportation Secretary Ray LaHood has been brought in by the Port Authority to conduct a separate review.

“The events that occurred at JFK airport this month were completely unacceptable,” the authority said in an emailed statement. In addition to its own independent investigation, “we will completely cooperate with the FAA’s inquiry.”