Residents in Greensburg, Kansas were given just 20 minutes to evacuate their homes and seek shelter after a stark tornado forecast was announced last year (07). The vicious winds ripped through the town, destroying 95 per cent of Greenburg's infra-structure and killing 10 people.

And DiCaprio is backing a campaign, entitled the Greenburg Project, which aims to completely renovate and rebuild the devastated town - bringing hope back to its citizens.

And the Romeo & Juliet actor admits he has been humbled by his charitable efforts.

He says, "I have the Greensburg project, which is rebuilding an entire city in Kansas. I'm continuing to work with outreach programs.

"The most profound lesson I've learned in all of this work is that people don't want to be told what to do or how to think."

DiCaprio is an avid social rights activist, backing campaigns urging Americans to vote at the forthcoming U.S. presidential elections in November (08), as well as a committed environmentalist.