Hastings, who was 33, was described by many of his colleagues as an unfailingly bright and hard-charging reporter who wrote stories that mattered. Most recently, he wrote about politics for the news website BuzzFeed, where the top editor said colleagues were devastated by the loss.
"Michael was a great, fearless journalist with an incredible instinct for the story, and a gift for finding ways to make his readers care about anything he covered from wars to politicians," said Ben Smith, BuzzFeed's editor-in-chief.
Smith said he learned of the death from a family member.
Authorities said there was a car crash early Tuesday in the Hancock Park neighborhood of Los Angeles that killed a man, but coroner's officials could not confirm whether Hastings was the victim.
Hastings won a 2010 George Polk Award for magazine reporting for his Rolling Stone cover story "The Runaway General."
His story was credited with ending Gen. Stanley McChrystal's career after it revealed the military's candid criticisms of the Obama administration.Hastings quoted McChrystal and his aides mocking Obama administration officials, including Vice President Joe Biden, over their war policies.
At a Pentagon ceremony for his subsequent retirement in 2010, McChrystal made light of the episode in his farewell address. The four-star general warned his comrades in arms, "I have stories on all of you, photos of many, and I know a Rolling Stone reporter."
When he died, Hastings was a contributing editor at Rolling Stone, where Managing Editor Will Dana was quoted Tuesday saying Hastings exuded "a certain kind of electricity" that exists in great reporters whose stories burn to be told.
"I'm sad that I'll never get to publish all the great stories that he was going to write, and sad that he won't be stopping by my office for any more short visits which would stretch for two or three completely engrossing hours," Dana said.
Hastings was also an author of books about the wars. "The Operators: The Wild and Terrifying Inside Story of America's War in Afghanistan" was published late last year and details shocking exploits of the military overseas.
In 2010, with the publication of "I Lost My Love in Baghdad," Hastings told the story of being a young war correspondent whose girlfriend died in Iraq.
In the summer 2013 issue of Vermont Life magazine, Hastings was quoted telling an audience at the Burlington Book Festival that he doesn't believe in objectivity in journalism.
"What I try to do is be intellectually honest in my writing," he said.
Hastings' family moved to Vermont when he was 16, a state he told the magazine was his "spiritual home." According to the magazine, he lived in New York with his wife.