Hint - do not throw more money at it. From Business Insider:
Mark Zuckerberg's $100 million donation to Newark public schools failed miserably — here's where it went wrong
In 2010, Mark Zuckerberg donated $100 million to Newark, New Jersey's failing public-school system with the intention of turning around the schools in five years.
The goals Zuckerberg set out to achieve — to enact a number of reforms that would make Newark a model city for education reform — are widely seen as a failure, journalist Dale Russakoff told Business Insider.
So where exactly did that $100 million go if the turnaround was a failure?
The union bureaucracy is too entrenched and powerful - they are negotiating themselves into irrelevancy. I am reminded again of this graph:
