How did supermassive black holes form?
An astronomer analyzed ancient supermassive black holes with mathematical models and found they likely grew exponentially after light, intermediate, and heavy seed stars merged.
So when a star collapses or collides with another star and the force is so strong that the only place for the force to go is inward is what creates a black hole. There's theories that the supermassive blackhole in the center of the Milky Way was formed by 2 stars colliding and creating a strong enough implosion to create Sagittarius A*. And there are more reports saying that the black hole became exponentially active about 200 years ago...