Salvador city police spokesman Vicente de Paula says 58-year-old Ivonete Pereira de Oliveira was a passenger on the bus that two gunmen held up on Saturday.
He says an armed off-duty policeman on the bus opened fire. In the ensuing gunbattle a bullet struck the left side of Oliveira's chest.
De Paula said Tuesday that the 150 reals (about $70) worth of bills that Oliveira hid inside her bra slowed the bullet enough to prevent it from entering her heart and killing her instantly.
Oliveira underwent surgery to remove the bullet from her left breast and was released from the hospital on Monday.
The off-duty police officer was killed.
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