The Brilliant White Light

I was looking across a city, staring at the broad expanse of the horizon. The sky was dark, and I could see lights scattered here and there. I was focusing on a place where everything seemed to converge, and suddenly I saw a brilliant white light form and expand across the horizon, expanding like a nuclear explosion. The light was pure white like, not yellow like the sun or like electricity that is blue, but pure white. I ran back to my house to find my family, knowing that the light would quickly spread over the whole region.