Nuke test, nuke accident or terrorist nuke attack.
Or a more mundane event such as a meteor/meteorite?
Doesn’t look like a nuke at all. A big nuke should give a flash, then dim, then brighten to nearly blinding intensity, then die out slowly. This brightens and then fades one time, over a fairly short period of time. Meteor or similar space junk.
IMHO, it did not look anything like a nuke. No bright, fast initial flash. It looked more like a gas explosion, slow and cascading ignition.
Also, no shockwave was apparent.
A nuke would have been as bright as sunlight, not orange.
Color indicates the burning of a metal at more normal furnace temps, not a nuclear reaction.