“This raises really serious questions, not just in the Boston area but also in the Charlotte area,” Rep. William Keating said.

VIDEO: Congressman Pushes For Answers In Stowaway Investigation

For the first time, Homeland Security Director Janet Napolitano publicly answered questions about the Delvonte Tisdale case. Investigators think the 16-year-old stowed away in the wheel well of a U.S. Airways plane at Charlotte's airport in November. His body was found in a suburb along the flight path to Logan International in Boston and his pants had what seemed to be aviation grease on them.

“Clearly if somebody -- a 16-year-old -- is able to circumvent those standards and requirements and get into the wheel well of a plane, there has been a breakdown,” Napolitano said.

Keating said the incident proves there needs to be tougher security and not just inside the airport but at the tarmac, as well.

“If it wasn't this young man who stowed himself for his own reasons -- if that had been a person with more nefarious motivation -- think about what would have happened to that 737 commercial airliner,” Keating said.

“We'll certainly continue to work with Sec. Napolitano on this case to see if there's a broader perimeter issue,” Michael Leiter, the national counterterrorism director, said.

After the hearing, Keating said he's still concerned because of all the unanswered questions. He added that he’s hoping to learn information on what exactly happened that day, what changes will be made to Charlotte's airport and see a full review of all the tarmacs across the U.S.