Sophia Bush's second cousin, nine-year-old Christina Green, was tragically killed on Saturday in the Tucson massacre, and the actress stepped out at the Hollywood premiere of "Green Hornet" on Monday night to share her grief.

“I think that more than anything it needs to serve as a reminder for us, for those of us who lost people there, and for those of us who didn’t, that life is really short and that you never know what’s coming around the corner and you can’t waste a day putting off seeing your family or making that phone call or telling someone you love that you do," Bush told FOX411's Pop Tarts. "I think it’s incredibly important that we get back in touch with our emotions as a society, and that we start being a little kinder.”

The "One Tree Hill" starlet also hopes the tragedy in which she lost her young relative will spur an increase in security and restrictions on firearms.

“It is hard. You don’t want to live in fear every day. You don’t want to have to walk through a metal detector to get into every building on the street but nobody should be able to walk into a public place with a gun," Bush added. "Nobody should be able to just get a gun. Things need to tighten up and get more secure overall.”

Hollie McKay has been a staff reporter since 2007. She has reported extensively from the Middle East on the rise and fall of terrorist groups such as ISIS in Iraq. Follow her on twitter at @holliesmckay