Fortunately, there is not a single black hole near the Earth. The closest candidate for this role is the name A0620-00 and is located approximately 2800 light years from us. However, this does not mean that she cannot kill us. The fact is, before the appearance of black holes, all-destructive supernova explosions occur, marking their birth. These explosions are capable of destroying all life on the planet, even if their epicenter is several thousand light years away.
Immediately after stars (or paired stars) collapse into a black hole, giant bursts of energy occur, which in science are commonly called gamma-ray bursts. The ozone layer that covers our planet is our natural defense against gamma rays from the Sun, but gamma rays from supernova explosions are thousands of times more powerful and can literally fry our planet on contact. Moreover, gamma-ray bursts are such amazing phenomena that they can even destroy the connections in our DNA.
Since this radiation is invisible, and its speed is equal to the speed of light, then, most likely, we will not even have time to understand if it hits us. Here we have a rainforest, and a minute later - the scorched wasteland from "Mad Max".
The good news is that gamma ray bursts are rare enough that they need to burst through our galaxy to be dangerous to us. Fortunately, no such violations of our borders have yet been noticed.
Below you can watch an animated video, which explains in more detail the process of gamma-ray bursts and what consequences they can cause on Earth. For those who do not know English, we advise you to turn on Russian subtitles.
NIKOLAY KHIZHNYAK