The guard who halted a group of 50 students from North Carolina from singing “The Star-Spangled Banner” during a visit to New York’s 9/11 Memorial was in the wrong, site officials said. In a video of the incident, the guard asked the students to stop singing because it fit the description of a “public demonstration,” which requires a permit at the site. “The guard did not respond appropriately. We are working with our security staff to ensure that this does not happen again with future student performances,” said memorial spokeswoman Kaylee Skaar. A school music teacher, Martha Brown, said that a different security guard initially granted permission for the middle-schoolers to sing. “We turned it into a teaching moment and taught them that even if you don’t agree with it, or understand it, you must respect authority."