I work at a Credit Union (WAY better than a bank)...
The perp walked in, popped off a shot, then proceded to threaten everyone while collecting $. He left within 90 seconds of entry. By a strange twist of fate, someone outside saw him take his mask off in his car as he sped off and thought it looked suspicious enough to follow him until he decided he'd better in case he'd get hurt - told the cops where he went, then led them to him. They caught up w/ him (he wasn't the brightest guy - actually drove up one of those loops where you basically don't have any way out. He went off the road then started taking pot shots at the cops who returned fire and hit him. He's currently in the hospital under guard last I heard.
My experience was... I heard the shot, then shouting, then my department and most people who were able to fled to our building next door. It's been a hell of a time since then... most of the people in the lobby were pretty traumatized by the event.