Your tone is typical, but it took me a whopping 30 sec to find this
http://www.nytimes.com/2016/12/04/us/warehouse-party-fire-oakland-search.html
Proof, as you seek, will come in the wake of criminal charges, but will likely never touch public officials...
That article is worth reading for the new information.
The body count is up to 33 now.
Oakland city zoning enforcement
http://www2.oaklandnet.com/government/o/PBN/OurServices/CityCodeEnforcement/index.htm
http://www2.oaklandnet.com/government/o/PBN/OurOrganization/BuildingServices/o/Code/index.htm