Jennifer Lawrence was totally in Katniss mode while greeting eager fans outside of 'The Late Show With David Letterman' last night, quickly jumping into action and sprinting to safety once the barricade holding back fans started to buckle.

Here's how the slightly scary sitch went down: The 'Hunger Games' actress had finished signing autographs for a swarm of fans and was heading back to her car -- that is, until she quickly changed her mind and generously decided to greet more fans. However, the sheer volume of people caused the barricade to break -- and J. Law was forced to sprint on outta there, Katniss Everdeen-style.

While we're sure she was bummed (she did purposely go back to meet everyone, after all!), the situation could have definitely escalated if fans had mobbed her. We're just glad everyone is OK!

Check out the video of the chaotic scene above.

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