Most dangerous airports in the US
1. Chicago O'Hare
In 2010, there were at least a half-dozen incidents in which airliners came close to colliding with other planes or helicopters - including in Chicago, Houston, San Francisco, Burbank, Calif., and Anchorage. In some cases, pilots made last-second changes in direction after cockpit alarms went off to warn of an impending crash.
In July, two Delta flights collided in O'Hare tarmacs.
O'Hare airport is undergoing a $6.6 million plan to realign its runways.