Friday’s firing of the New London public works director after the surfacing of yet more safety violations at the Solid Waste Transfer Station is the latest and most serious indictment of Mayor Daryl Justin Finizio’s failure to appoint experienced and qualified personnel to key positions.

The appointment of now-fired Public Works Director Tim Hanser by Mayor Finizio, soon after his election in 2011, made no sense from the start. Here was a department with a problem-plagued history in an urban setting that places special demands on public works services, and the mayor appointed a director with no experience.

When appointed to the post, Mr. Hanser was the local campaign chairman for the New London Green Party, a former senior associate scientist for Pfizer Inc. who had previously worked as a high school chemistry teacher in Brooklyn, N.Y. He has a Bachelor of Science degree from Purdue University and master's degree in science from Pace University and is fluent in Spanish.

Asked how any of that prepared Mr. Hanser to lead Public Works, the mayor at the time called him an “innovator” who will “bring dynamic new leadership.”

Mr. Hanser has probably done some good things. The mayor praised his leadership during the city’s response to Superstorm Sandy in 2012. But the problems have been very serious.

In January 2014 a city resident died, crushed after he fell into a compactor at the transfer station. The state had cited the city for “willful” and “serious” safety violations, including the failure to have railings to prevent a fall into the compactor.

Two months ago came the firing of worker Mounir Hage, allegedly for taping down a plastic knob intended to prevent the compactor from running automatically. The city suspended four other public works employees at that time.

Then on Friday came the firing of two more workers, again for safety violations, and the dismissal of Mr. Hanser. The mayor also disciplined a third employee.

Given the repeated disregard for safety, in defiance of a “zero-tolerance policy,” there is no question the director had to be held accountable. It is a fair question to ask if the change should have come sooner.

Moving forward, Mayor Finizio or the person who succeeds him after the November election must make it a priority to appoint qualified, experienced directors. Also in order is a charter change that would require council approval of key mayoral appointments. Lessons need to be learned.