"Nobody is safe here. At any moment the life may be finished. Nobody can guarantee. Padaṁ padaṁ yad vipadām (SB 10.14.58). In the śāstra it is said that here in this material world there is danger in every step. You are walking very nicely, and sometimes suppose there is a skin of plantain, and you slip, and your leg may be broken. Padaṁ padam. Even walking, even sitting—heart failure.
So there is no guarantee. Any moment we can die. And it is therefore called mṛtyu-loka, 'The place where death is,' I mean to say, 'sure.' 'As sure as death.' People give surety example: 'As sure as death.' As nobody can avoid death, it is sure. You may be very strong and stout in your health and go on exercising on the beach daily, but you can die any moment. There is no guarantee. But everyone wants akuto-bhayam: 'There may not be... I must be very safe and sound in every respect, in my social position, so far my health is concerned, anything.' Everyone wants that security. But there is no security."
(Srila Prabhupada Lecture, Bombay, December 11, 1974)