The pilot killed in a helicopter crash landing on a high-rise building in midtown Manhattan on Monday should never have been in the air, Federal Aviation Administration officials said on Tuesday.

Timothy McCormack did not have the proper license to fly in low-visibility conditions, the FAA told NBC and The Hill . The New York City area on Monday was obscured by clouds and rain throughout the day, including at the time of the crash.

Although the crash caused a fire atop the AXA Equitable building, people were quickly evacuated and nobody else was harmed. Emergency vehicles rushed to the scene as the news broke and memories of the 9/11 attacks on the World Trade Center flooded the minds of New Yorkers. Mayor Bill de Blasio (D) assured the city that nothing like that was happening.

There is no indication at this time that this was an act of terror, de Blasio said in a news briefing on Monday. And there is no ongoing threat to New York City.

It remains unclear what exactly caused the crash. The National Transportation Safety Board is currently investigating. But in the wake of the crash, a proposal to ban non-essential helicopter flights in New York City was raised again.

This pilots death is one too many, Rep. Carolyn Maloney (D-N.Y.) said in a statement on Monday. We cannot rely on good fortune to protect people on the ground. It is past time for the FAA to ban unnecessary helicopters from the skies over our densely-packed urban city. The risks to New Yorkers are just too high.