Fish typically die in aquaria because of:
Old age
Disease
Low oxygen content in the water
Toxins in the water, some of which consume its oxygen
Starvation from lack of feeding
Overfeeding, which can decrease the oxygen content of the water
Predators
guppies
Simon Fish died in 1531.
Emily Fish died in 1931.
Jasper Fish died in 1791.
William Fish died in 1866.
Bert Fish died in 1943.
Preserved Fish died in 1846.
Fish Markham died in 2000.
Nicholas Fish died in 1833.
George Fish died in 1977.
Drounding
It's because when the fish died there wasn't any life for the tale.
Well my fish could , i don't know about yours............. :D (my fish died yesterday)