Construction workers begin the demolition of an abandon building that was a location of high crime and drug sales.

The city began demolishing a number of buildings in neighborhoods on the South and West sides Thursday, as part of a Mayor Rahm Emanuel-backed strategy to cleanse neighborhoods of gang activity.

Certain vacant buildings attract gang activity and violence, Emanuel contends, and they need to come down.

Some are in such disrepair that they need to be demolished, said Caroline Weisser, spokesperson for the city’s building department.

But housing advocates, like the folks at Action Now, want the city to use funds from the infrastructure trust to rebuild neighborhoods.