Steve Kastenbaum

ASDX is a runway safety system which allows air traffic controllers to track surface movement of aircraft and vehicles.

So in this case, that vehicle did not have a transponder.

There were two people in the cab, two people in the tower cab.

Investigators zeroed in on what the people in LaGuardia's control tower could see on their screens before the crash.

But NTSB Chair Jennifer Homendy said the controllers couldn't see information about the fire truck's exact location.

It's not clear whether different controllers were talking to the pilot and the driver of the fire truck Sunday night.

Investigators are set to interview the controllers soon.

For NPR News, I'm Steve Kastenbaum in New York.

Investigators zeroed in on what the people in LaGuardia's control tower could see on their screens before the crash.

But NTSB Chair Jennifer Homendy said the controllers couldn't see information about the fire truck's exact location.

It's not clear whether different controllers were talking to the pilot and the driver of the fire truck Sunday night.

Investigators are set to interview the controllers soon.

For NPR News, I'm Steve Kastenbaum in New York.

Investigators zeroed in on what the people in LaGuardia's control tower could see on their screens before the crash.

But NTSB Chair Jennifer Homendy said the controllers couldn't see information about the fire truck's exact location.

It's not clear whether different controllers were talking to the pilot and the driver of the fire truck Sunday night.

Investigators are set to interview the controllers soon.

For NPR News, I'm Steve Kastenbaum in New York.

The procedure always is in deference to the control tower.

anytime anyone is moving on any of our runways or taxiways.