O'Hare International Airport wasn't the worst in the nation for intruders penetrating security fences and gates in a 13-year study of 30 major U.S. airports.
But neither was the nation's second-busiest airport the most secure with 10 security mishaps between 2004 and mid-February 2016, The Associated Press is reporting.
Midway International Airport fared better with just two breaches of perimeter fencing and gates since 2016. The worst offender was San Francisco International Airport with 41. The total number of violations came to 345, AP said.
Some of the O'Hare intrusions included a man hoisting a bicycle over a fence in 2010 and riding around before being arrested and an intoxicated driver smashing his Mercury Sable through a gate in 2006.
But others raise concerns such as a man who sneaked in through a security checkpoint when the gate was raised and was found to have a loaded pistol in January 2015.
"The secured area is fenced in and access is monitored by Chicago Department of Aviation, Aviation Security Units," CDA spokesman Owen Kilmer said. "As far as breaches go, the CDA utilizes a layered security approach to ensure unauthorized access is detected, responded to and prevented."
With about 26,000 commercial flights daily in the U.S., 345 breaches "is not good but it's not that bad either," University of Illinois at Urbana-Champaign aviation security expert Sheldon H. Jacobson said.
"It's very possible they're catching 99 percent and a small percentage is getting through. There are layers of security beyond the perimeter fencing ... and no one reports the attempts that are stopped."