(AP) - Recent incidents of illegal access to the World Trade Center tower have led to a security shake-up.



The Port Authority of New York and New Jersey announced Wednesday that a company that provides unarmed security at the region's airports will also perform that function at the trade center. Allied Barton's contract will be increased by about $60 million with the new duties.



Three parachutists jumped from the top of 1 World Trade Center last fall, and in March a New Jersey teenager climbed to the top of the 1,776-foot tower's spire.



Summit Security Services had been providing unarmed security at the World Trade Center and will continue to provide security at other Port Authority facilities.



Allied Barton was hired for airport security last year.