Investigators from the US federal agency noted that mid-air collisions like this are rare in the US, and they said it was far too early to speculate on what caused the crash; however, we will look at crowded airspaces and complex issues surrounding airports.

Throughout the program, we will be joined by two guests on opposite sides of the world: Karen Percy, Senior freelance reporter, who's in Melbourne, and Emily Peck, Markets correspondent at Axios, in New York.