BOSTON — Chaos erupted near Boston Common Monday afternoon when a man was spotted marching down Tremont Street with a large kitchen knife in hand — until a brave pedestrian jumped in and took him down with nothing but a stick.

The suspect was seen walking toward City Hall Plaza around 4:40 p.m., triggering a rush of Boston Police cruisers as officers scrambled to intercept him. But before they could arrive, witnesses say a bystander stepped up, rushed the armed man, disarmed him, and tossed the knife into a nearby sewer.

Moments later, BPD officers swarmed the scene and placed the suspect in custody. EMS responded to evaluate the man for a mental health crisis.

According to real-time scanner reports, the hero civilian used a “short stick” to chase and subdue the knife-wielding suspect — a gutsy move that likely prevented a potential tragedy during the busy evening rush.