how did naruto's mom die
She was Kushina uzumaki. She was brought in konoha for sole purpose to be made jinchuriki from other village because of her sealing jutsu that could seal tailed beast. She was then made jinchuriki and she married Minato namikaze and had Naruto. But at the night when she had naruto a masked man attacked konoha and tried to unseal kyuubi and succeed in it. That night both Minato and Kushina died saving the village from kyuubi's attack.