Updated

Three skydivers say they spent about four hours atop 1 World Trade Center in New York City before parachuting off it in a stunt that raised questions about security and left them facing felony charges.

James Brady, Marko Markovich and Andrew Rossig mentioned the four-hour timeframe in court papers Tuesday. They acknowledge making the Sept. 30 jump but pleaded not guilty to burglary and other charges.

They were arrested last month, shortly after a teenager was accused of climbing the as-yet-unfinished tower.

The incidents have spurred concerns about how tightly the security-conscious trade center is actually protected. The teen and the parachutists say they got in through holes in the perimeter fence.

Site owner the Port Authority of New York and New Jersey hasn't immediately responded to an inquiry.