Bryant's pilot's final exchange with air traffic control could be a key clue to the crash

As investigators scour for clues in the helicopter crash that killed nine people, including NBA legend Kobe Bryant, the pilot's last words with air traffic control illustrate a foggy scene in the sky.

Pilot Ara Zobayan said he was climbing to avoid a cloud layer.

The National Transportation Safety Board member Jennifer Homendy said, but when air traffic control asked him what he planned to do, there was no response.

Visibility was so low Monday morning that the Los Angeles Police Department had decided to ground its helicopters that morning.

But it's still not certain what caused the helicopter to crash, killing parents, children, and one of the greatest athletes of all time.

Bryant,  and his daughter Gianna, were heading to a basketball game in Thousand Oaks, where he was expected to coach and she was expected to play.

Moments before the crash, the pilot received SVFR clearance -- or special visual flight rules clearance, according to audio recordings between the pilot and air traffic control.

SVFR clearance allows a pilot to fly in weather conditions worse than those allowed for regular visual flight rules.

It is being reported that after the pilot requested special permission to fly through the area, the helicopter circled for 12 minutes until air traffic control approved SVFR clearance.

[Source: CNN]