Technically, a crocodile will not die of old age. Instead of aging, they grow physically as they get older.
But that doesn't mean they're immortal. Crocodiles will continue to die for some reason, but not of old age.
So the question now changes to...
Do crocodiles not age? Why?
To understand this, you need to know about "Senescence".
Senescence is a term used to indicate the gradual deterioration of the body's physical appearance with age. More simply, you can call it "aging."
Aging is generally characterized by muscle weakness, decreased mobility, worsening sensory acuity, and age-related diseases. You can clearly see the effects of aging in humans.
The weakest and most defenseless must become larger. And of course, this increases the risk of death.
But this is not the case for some species, such as crocodiles, turtles, sea urchins, lobsters, clams, and others. They show almost no signs of aging; one could say they are "biologically" immortal.
Species like this only die from diseases, accidents, disasters, or predators.
That's why there's a giant tortoise that reached the age of 255 and died in 2006 at the Kolkata Zoo in India. Or there are also shells on the coast of Iceland that are 507 years old.
Broken senescence clearly shows why crocodiles don't die of old age. Therefore, a 70-year-old crocodile is not very different (in terms of physical strength and agility) from a 6-year-old crocodile.
Although they cannot die of old age, nature has a way of killing them. Crocodiles mostly die from starvation or disease.
They will continue to grow as they age and need more food. When food supplies do not meet their needs, they may starve to death.
Therefore, crocodiles will not die of old age because the senescence system in their bodies is not functioning.