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Just two days after her second cousin Christina Green was killed in the shooting near Tuscon, Arizona, Sophia Bush opened up about what the tragedy has taught her.

"It's been a lesson more than anything for me and for my family that life is incredibly short," the One Tree Hill star, 28, said on Monday's Chelsea Lately. "You've gotta take every day and tell the people you love that you do."

And while the actress noted "it's easy to get heated and to scream and yell about what's going on in this world," she stressed the importance of not letting things get out of hand.

"It's really important for all of us to take a step back," she said.

Bush also shared her thoughts about the incident -- which left six dead and critically injured more than a dozen others, including Arizona congresswoman Gabrielle Giffords -- on Twitter, writing, "How can this be? Violence is never the answer."