Pamela Engel AND Michael Kelley JUN. 21, 2013, 5:01 PM | Business Insider

About 15 hours before dying in a fiery car crash at about 4:30 a.m. in L.A. on June 17, journalist Michael Hastings sent an email to several colleagues that said the FBI was investigating him and he was "onto a big story."

The 33-year-old had been working as a BuzzFeed writer and Rolling Stone contributing editor at the time of his death.

The subject line of the email, obtained by Los Angeles news station KTLA, was "FBI investigation, re: NSA."

Here's the full text:

Hey [words blurred out] — the Feds are interviewing my "close friends and associates." Perhaps if the authorities arrive "BuzzFeed GQ", er HQ, may be wise to immediately request legal counsel before any conversations or interviews about our news-gathering practices or related journalism issues.

Also: I'm onto a big story, and need to go off the [radar] for a bit.

All the best, and hope to see you all soon.

Staff Sgt. Joseph Biggs, who met Hastings when he was embedded in Biggs' unit in Afghanistan, described the email as "very panicked."

"It alarmed me very much," Biggs told KTLA. "I just said it doesn’t seem like him. I don’t know, I just had this gut feeling and it just really bothered me."

The FBI has denied it was ever investigating Hastings, and police do not suspect foul play in his death.

It's not clear what "big story" Hastings was referring to in his email, but he reportedly had been talking to his boss, BuzzFeed editor Ben Smith, about a story on Barrett Brown.

Brown, a journalist affiliated with the amorphous hacker collective Anonymous, was arrested for threatening an FBI officer and sharing a link to stolen credit card information taken from Stratfor. The 31-year-old, who faces up to 100 years in prison, is in jail awaiting a September trial.

The LA Times notes that Hastings was also researching a story about a privacy lawsuit brought by Florida socialite Jill Kelley against the Defense Department and the FBI.

And the subject line mentions the NSA, which has been in the news all month.

Hastings is best-known for his Rolling Stone cover story called "The Runaway General" that led to the resignation of the commander of the entire Afghanistan War, General Stanley McChrystal. He also wrote about the Petraeus scandal and media's cozy relationship with military elites.

Wikileaks tweeted this message on Wednesday:

No other vehicles were involved in the crash, and officials are working to determine whether the car Hastings was driving had any mechanical problems.

Hastings' car, which was reportedly going very fast, burst into flames as it crashed into a tree.

Read more: http://www.businessinsider.com/michael-hastings-email-about-fbi-inv...