About three dozen surveillance cameras at Newark Liberty International Airport will be wired with sensors designed to sound an alarm when the camera malfunctions. The upgrade comes after a Chinese student slipped past a guard in January to see his girlfriend, causing a massive security alert. The camera that should have recorded the incident had been out of service for six days, investigators found. TSA officials praised the effort to upgrade cameras at the airport. "TSA is pleased the Port Authority is taking proactive steps to enhance the performance of its airport surveillance cameras and ensure the system alerts personnel when operational issues need to be addressed," a spokeswoman said.