GOIANIA, BRAZIL -- Struck with grief, tens of thousands of fans gathered Saturday to pay tribute to Marília Mendonça, one of Brazil's most popular singers who was killed a day earlier in an airplane crash at age 26.The Latin Grammy winner and four other passengers, including her producer and uncle, perished Friday when their plane crashed while flying from Mendonça's hometown of Goiania in Goias state to Caratinga, a small city in Minas Gerais state north of Rio de Janeiro.Some mourners arrived