According to a brief announcement on Biggovernment.com, Andrew Breitbart died shortly after midnight in Los Angeles. No details have been released.

Andrew passed away unexpectedly from natural causes shortly after midnight this morning in Los Angeles.

We have lost a husband, a father, a son, a brother, a dear friend, a patriot and a happy warrior.

Andrew lived boldly, so that we more timid souls would dare to live freely and fully, and fight for the fragile liberty he showed us how to love.

This is a major loss for conservatism. Andrew was a sparkplug, full of energy and ideas. He got things done. His family has our deepest sympathy. He leaves behind a widow and four children.

UPDATE

Ed Morrissey writes at Hot Air that Andrew Breitbart was "our Merry Prankster":

He was willing to take risks and look foolish in order to make a point or win an argument, with more courage than most would muster.  No one who saw it will ever forget how he seized the podium at Anthony Weiner's press conference and demanded vindication from media outlets who had been disparaging him and defending Weiner when the former Congressman got caught literally with his pants down.  Few men have had the kind of impact Andrew did in such a short time, and he leaves behind a media empire that is still gaining strength.

Breitbart had a zest for political combat. He reveled in being a polarizing figure. He had a genius for getting the goat of the opposition and never apologized for his swashbuckling style of journalism.

In the ancient world, opposing kings preparing for war would send out their champions to engage in single combat, sometimes to decide the outcome of the conflict, more often to indicate which side God was on. Andrew Breitbart was a conservative champion. But instead of riding out to meet a single warrior, he gladly sallied forth - sometimes alone - to combat the entire left. Along the way, he picked up many allies - and made many enemies. Win or lose, it seemed that most of the time, God was indeed on his side.

But if "A man's greatness can be measured by his enemies," so, too can it be judged by his friends. Don't listen to the prattling left today. Simply remember a man, made for his time, unique in his abilities, who left us for a far, far better place.

Greg Halvirson adds:

Breitbart, lightning and lodestar, was activism personified, a raging pioneer in the media revolution.  Courageous, fearless, tireless.... He was these and more, an adjective train--irascible, irreverent, iconic, IN YOUR FACE.

I'm reminded of another Andy-- Kaufman.  Both men were controversial. Both gored the ox, punked paradigms, and "flipped tables."  But unlike Kaufman, Andrew was serious, his focus keen on the propaganda of the left, the false premises and the lies.  He leaves behind four children, but more than this, Andrew leaves a legacy: the Drudge Report, Big Hollywood, Big Journalism, Big Government....  These scratch the surface.  In parting, he roars.

Jack Kerouac once said of himself:

"The only people for me are the mad ones, the ones who are mad to live, mad to talk, mad to be saved, desirous of everything at the same time--the ones who never yawn or say a commonplace thing, but burn, burn, burn, like fabulous Roman candles, exploding like spiders across the stars...."

Mad to live--that was Andrew.  He and Jack would be pals.

Greg Halvorson is the founder of The Conservative Hammer and hosts Freedom Warrior Radio on Blog Talk Radio.  Follow him on Twitter at @GHalv.