Some people in SF and the East Bay heard the booming of fireworks, and some had the pleasure of watching an impromptu show over Treasure Island Wednesday night. But what holiday was this for?

The answer is there was no holiday or special event you missed. The fireworks — which were significant and appeared to be getting shot off from several spot across Treasure Island — were the product of "film activity," according to a Monday tweet that no one likely saw from the Treasure Island Development Authority. And no, no one is saying what movie was being shot.

The show went on for about an hour — the notice on Monday had said "between 8 and 10 PM" but the setup apparently took a little while, and the booming didn't start until around 9:30 and went to about 10:30 on Wednesday night, as KRON4 notes.

Those who live on Telegraph Hill or in a SoMa high-rise facing the Bay would have had the best view. And those who are early-to-bed types were likely awakened and annoyed.

We'll update you if we get any intel on who's shooting a movie in SF right now.