What happens near a black hole

The supermassive black hole Sagittarius A* lies at the center of the Milky Way. Beyond its event horizon, neither light nor a signal can escape. But saying that any life must die instantly at the boundary is too categorical: near the horizon of a very massive black hole, tidal forces can be weaker, so in theory a traveler could cross without noticing the boundary at that moment. Escape would then be impossible, and tidal forces would eventually destroy the body.