The woman, identified as Amanda Ferraz Geremias, died in hospital, according to a police report, leaving club officials stunned.
"This was a very big tragedy," club president Andres Sanchez was quoted as saying on the website of the daily Folha de Sao Paulo, adding that the club would do all it could to help the woman's family.
The announcement of a new stadium was the high point of the team's centenary celebrations, which included Brazilian President Luiz Inacio Lula da Silva attending an all-night party on Tuesday with thousands of fans.
The venue, to be called 'Fielzao' ('Big Faithful') as a tribute to the club's fans, known as 'the faithful', will have a capacity of 48,000 which could be increased to 65,000 if chosen for the World Cup's opening match.
"The biggest gift to the fans will be this blasted stadium," said an emotional Sanchez. "Now we'll have our own home."
Although they are the most popular club in Sao Paulo and the second in Brazil after Flamengo, Corinthians are the only one of Paulista's four major clubs without a home of their own.
