The Super Bowl is one of the largest events in the nation, and this year’s big game in Atlanta was no exception. An estimated one million people visited the city. City officials and law enforcement began preparations for the event two years ago, and worked with more than 40 local, state, and federal law enforcement agencies to ensure a safe and secure event.

A little more than a week before the event, the city opened its Joint Operations Center, which included representatives from state, local, and federal agencies, utility providers, and the local public transportation agency.

Around 75 to 100 officers were stationed at the Joint Operations Center, reported Fox 5 Atlanta.

Officers patrolled the area in patrol cars, on motorcycles, on horseback, and on foot with detection dogs. Law enforcement also monitored crowds from above with helicopters, reported the Epoch Times.

To secure an outer perimeter to prevent an attack by vehicle, the Atlanta Police Department created a barricade of sanitation trucks, cement trucks, and water-filled barricades, its police chief told CBS News.

In addition, the Atlanta Fire Department made sure it was fully staffed to respond to emergencies, and deployed EMS bicycles to respond in crowded areas.

For the duration of the event, the city issued a ban on drone use around the stadium during the big game. Customs and Borders Protection were among the federal agencies offering support for the event. The agency flew in six helicopters to provide aerial surveillance and enforce the designated no fly zone, reported WSBTV.