The female pilot of the Black Hawk helicopter that collided with an American Airlines flight made several critical errors and ignored a warning from her co-pilot, according to the New York Times.

The tragedy, which claimed more than 60 lives, was the result of a series of mistakes, the NYT reports.

In the moments leading up to the crash, not only was the Black Hawk flying at an incorrect altitude, but its pilot, Captain Rebecca Lobach, also failed to follow a directive from her co-pilot, Army flight instructor Warrant Officer Andrew Eaves, to change course.

According to the report, Eaves advised Lobach to turn left toward the East River bank, believing that was what air traffic control intended. Turning left would have created more space between the helicopter and American Airlines Flight 5342, which was descending toward Runway 33 at approximately 300 feet. Lobach, however, did not turn left.

While the report also points to shortcomings by the air traffic controller, it highlights that the final opportunity to avoid the collision was missed when Lobach ignored her co-pilot’s warning.