La ExcluZIHón del Pueblo

The deafening discordant thump last night from the Pier went on past 10pm and from La Playa Madeira, sounded like it was next door
Was that also a govt sponsored event?
Can we write to someone?

Yes, it most certainly was. The current mayor made all kinds of promises years ago during his first election campaign about getting noise pollution under control, but his administration has done exactly the opposite by either sponsoring extremely noisy events during hours of rest or by authorizing them.
You can make a complaint via the city government's website or their Facebook page.
https://zihuatanejodeazueta.gob.mx/contactomac
https://www.facebook.com/Gob.Zihuatanejo/