DC Fire: 'We don't believe there are any survivors' after helicopter collides with passenger jet

A mid-air collision occurred over the Potomac River involving an American Airlines jet and a U.S. Army Blackhawk helicopter, resulting in the presumed deaths of all 67 people on board both aircraft. The NTSB is leading the investigation to determine the cause of the crash, which happened despite clear weather conditions. Recovery efforts are ongoing, with 28 bodies recovered so far. The incident has raised concerns about airspace congestion in the Washington, D.C. area, a topic discussed by officials including Senator Tim Kaine. The Blackhawk involved was on a training mission, and questions remain about the visibility and actions of the crew.

What were the main concerns expressed by officials regarding airspace congestion?

What type of helicopter was involved in the crash?

What is the significance of the location where the crash occurred?