A resonance cascade is a generally disruptive and physically dangerous energetic event which tends to rip open holes in the dimensional fabric of reality.

Did the G man cause the resonance cascade?

In Half-Life, G-Man is the source of the Xen crystal that ends up causing the resonance cascade at Black Mesa. He also strongly pushed for the experiment to move forward. We know this from Eli Vance in Half-Life 2: Episode 2.

Who survived the Black Mesa incident?

During the mayhem, three survivors made their way to the surface and called in the military to help them with the alien onslaught. The survivors were Dr. Gina Cross, Dr. Colette Green and Dr.