A 16-year-old boy was arrested on Sunday for allegedly trespassing onto the rooftop of the World Trade Center, the Associated Press reported.

Joe Pentangelo, a spokesman for the Port Authority of New York and New Jersey, said the boy was charged with misdemeanor criminal trespass.

According to Pentangelo, the boy got into the site through a 1-foot opening in a fence and entered the building by climbing the scaffolding. The guard of the 104th floor did not see him, and he has since been fired.

It is unknown how exactly the unnamed boy went unnoticed on the 104th floor. 

After he was arrested on the site, the teen's camera and cell phone for seized after officials obtained a search warrant. Though a motive has not been determined, WABC-TV reported that he stayed on the rooftop to take pictures for about two hours.

Authorities are still investigating whether the sneaky teen got into any other parts of the building.

"We take security and these types of infractions very seriously and will prosecute violators," said Joe Dunne, chief security officer for the Port Authority, in a statement. "We continue to reassess our security posture at the site and are constantly working to make this site as secure as possible."  

Though the WTC has not opened yet, it will contain a $40 million security system with barriers, guard booths, and sally ports, which will check vehicles for dangerous materials.