After Mello kidnaps Takada (the spokes person for Kira (Shes a Kira supporter) and tries to make his escape Takada manages to contact Light Yagami (or Kira) and tell him that she has been kidnapped and locked in the back of a semi. Light asks her if she remembers what he had said to do if she was to get into a situation like this and she says yes. And one of those things was to kill Mello if the occasion arised that had the chance.
So before she Even made the call to light she had already had kiiled Mello. They already knew his real name which is Mihael Keehl. So that's how he dies.
Mello died of a heart attack. Kiyomi takada wrote his name on a piece of the desth note she had hidden on her. =(
Ingeborg Mello died in 2009.
Al Mello died on 1993-10-31.
Big Mello died on 2002-06-15.
Anthony de Mello died in 1987.
Francisco Manuel de Mello died in 1666.
Pedro Collor de Mello died in 1994.
Froilano de Mello died on 1955-01-09.
Albert Mello died on August 14, 2006, in Henderson, Nevada, USA.
Anthony de Mello - cricket administrator - died in 1961.
Sophia de Mello Breyner Andresen died in 2004.
José Mentor Guilherme de Mello died in 1928.
Cândido Firmino de Mello-Leitão died in 1948.