TMZ has obtained the horrific 911 call placed by Junior Seau's girlfriend moments after the NFL legend shot himself in the chest Wednesday morning at his Oceanside, CA home.
Junior's GF Megan Noderer (below) is so hysterical during the call she can hardly speak -- claiming she had just returned from the gym (around 10AM) when she discovered Junior's bloody body.
Megan tells the dispatcher, Junior wasn't breathing when she arrived and had appeared to have shot himself "in the heart."
Authorities responded and attempted to revive Seau, but life-saving efforts were unsuccessful. Seau was pronounced dead on the scene soon after. He was 43.
Seau's family claims he exhibited no signs of depression before his death -- but has since donated his brain to be studied for concussion research.
As we previously reported, the manner in which Seau killed himself -- gunshot to the chest -- is leading many to believe he wanted to leave his brain intact so researchers could study the long-term effects of concussions sustained in the NFL.