When a modified virus meant to cure cancer mutates, it turns all of New York into blood-sucking vampire-like creatures. Just one immune person, military virologist Robert Neville (Smith), is seemingly all that remains of the city. The terrifying early moments when the virus begins to mutate are revealed to us in a series of flashbacks.

In the first flashback, we learn that New York City is being quarantined, and Neville rushes through traffic to get his family out of the city. We also meet the German Shepherd puppy Sam, who will become Neville’s lone confidant in the apocalyptic new world. But it’s the subsequent flashbacks, when they reach the Brooklyn Bridge, where things escalate.

As the Nevilles near the evacuation point, the camera swoops up to reveal the Brooklyn Bridge as we’ve never seen it before. It is a frightening scene as droves of people surge toward New York’s East River in hopes of escaping the island before a mandatory quarantine begins. According to The Hollywood Reporter, the scene called for 1,000 extras, 160 National Guard members, and a 250-person production team.

And that didn’t even account for preparing the bridge itself.