The other day the whole street I was routed too was blocked by the police and firefighters ( have to go for alternative routes for many, many blocks ) and when I try to report it in the map didn’ found this option
LostInMyMaps - Volunteer Editor commented
The great thing about Waze is it is the community helping the community. You can report the closure in the app to help other drivers avoid the same closure. Details on how to report different hazards, including closures here: https://support.google.com/waze/answer/6262574
Waze only lets you report closures on roads you're nearby in the app and usually only ahead of you. Next time, try reporting the closure earlier, if it is safe to do so.