(CNN) -- The motorsport community was in mourning on Monday as competitors from across various racing disciplines paid tribute to Marco Simoncelli, the Italian MotoGP rider who lost his life after a crash in Malaysia on Sunday. Simoncelli, 24, sustained critical injuries when he was struck by compatriot Valentino Rossi and American Colin Edwards after losing control of his Honda bike and sliding across Turn 11 of the Sepang Circuit. Rossi, a seven-time MotoGP world champion, used the @ValeYellow46 Twitter account to pay tribute to Simoncelli, who he described as "a younger brother." "Sic [Simoncelli's nickname] for me was like a youngest brother. So strong on track and so sweet in the normal life. I will miss him a lot," read the Tweet.
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The motorsport community is in mourning after death of Marco Simoncelli
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Simoncelli lost his life after a fatal crash in Malaysia on Sunday
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MotoGP legend Valentino Rossi has described Simoncelli as like a brother
"Only that you will be missed - rest in peace @placeholder."
"He was one of the most charismatic figures in the world championship and had a fantastic future ahead of him in @placeholder.