The plumbing is another story..and they won’t be the first to screw up that in buildings.
As for warnings to the squatters...they had plenty and then some...more importantly willing hands to help them have a roof over their head otherwise ...they refused.
You can lead a horse to water but you can’t make him drink....and if he reuses consequences will follow.
These are not..the poor...Jesus alludes to...these are chemically addicted people who refuse offers to help. They want their lifestyles as they are.
No, it isn’t expected that a church will do such things illegally.
There are no warning signs, which is moot anyway since the city building department found out what they had done and is forcing them to hire a plumbing contractor to remove the system.