PHOENIX - Three people have been fired, two demoted and one suspended for a week after an investigation into flooding at the Burton Barr Library.

The city investigation determined the six individuals knew about problems with the sprinkler system for at least a year and a half and did nothing to fix it.

The Burton Barr Library remains closed after suffering extensive damage following a monsoon storm.

But the building's damage came from a sprinkler system the city said had been defective for years. When the system became pressurized, it leaked both air and water. The monsoon storm caused the system to pressurize,sending 50 to 60 gallons of water per minute throughout the building, according to fire officials.

The disciplined employees range from a building facilities administrator to the deputy public works director, who was suspended for a week. Two employees retired rather than accept punishment, city officials said.

"They had at least 18 months of knowing, or should have known about it," Phoenix City Manager Ed Zuercher said, "and [they] did not do anything."

The report also identifies City Fire Marshal Mike Abegg as being under investigation for failing to review reports of the sprinkler system's failures.

The repot also said Abegg knew about the sprinkler system's problems, but called it a "maintenance concern" instead of a fire-safety hazard.

The Phoenix Fire Department confirmed Abegg is still under investigation, as are several other department employees, but declined to comment further.

PHOTOS: Burton Barr Library experienced storm damage

The city estimates cleanup and repair will cost $10 million, and the city manager wants it to be done by June 2018.

A temporary library will be set up at Park Central.