NEW : FAA clean - up crews assessing damage at key air traffic control center . Aircraft allegedly tried to ' take out ' Chicago En Route , while attempting takeoff . Thousands of flights at Chicago and Midway airports cancelled since . Ripple effects felt at airports across the country .
NEW : FAA clean-up crews assessing damage at key air traffic control center . Employee allegedly tried to 'take out ' Chicago En Route Center while attempting suicide . Thousands of flights at O'Hare and Midway airports canceled since . Ripple effects felt at airports across the country .