NEW ORLEANS – A fire that crippled the turbines that generate power for the city’s pumps only complicated matters for an antiquated system that has been the victim of age and poor maintenance during the years.

Four of the five turbines generate an uncommon kind of electricity known as 25-cycle power, which the S&WB generates on its own. The fifth turbine generates modern 60-cycle commercial electricity Entergy provides.

The fifth turbine was the only one in operation Thursday and while it can convert its 60-cycle power to 25-cycle power to run the older turbines, there is a limited supply of power to spread among the pumping stations.

MORE: S&WB now says 16 pumps were not working during flood

If rain pours over the city, operators at pump stations will have to call in to the Claiborne plant to ask for power to run the pumps. A regular summer shower likely would not be an issue.

But if storms such as those from Saturday and July 22 pop up and dump large amounts of rain across the city, pump operators from all east bank plants on the west side of the Industrial Canal will call for the converted but limited power to run their pumps. Not all necessary pumps will be able to run, and the flooding Landrieu fears could happen.

“We are at risk,” Landrieu told the S&WB board during a special meeting he called Tuesday, since there is no redundancy in place at the plant.

Fire and floods: what we know now

How did the S&WB get to this point? Details the S&WB released today tell a mixed tale of long-term issues and recent breakdowns combining for a perfect storm of pumping problems.

- Turbine 1 caught fire Wednesday night. Officials don’t know how long it will take to fix.

- Turbine 2 no longer exists. In fact, it was taken offline back in the 1970s.

- Turbines 3 and 5 broke in May and July, respectively. Engineers hope to have them working again soon. The combined price tag to fix them comes in at $36 million.

- As for turbine 4, it hasn’t worked since 2012. It’s supposed to be fixed by December after a $15 million repair job.

- That’s left turbine 6 to handle everything on its own – pumping, water and sewage – until turbine 1 is repaired.

It’s a lot for one piece of equipment to handle, and right not there is now backup system. The city, however, has called in at least a dozen generators as a failsafe measure in case Entergy power drops.

The 25-cycle turbines were considered antiquated as long as four decades ago.

A 1975 article in The States-Item said that in May 24 of that year a steam pipe on a turbine exploded. It caused $150,000 worth of damage and "sharply" reduced the city's pumping capacity.

Then-General Superintendent G. Joseph Sullivan told the newspaper a 60-cycle system was needed and he expected one would be in place by 2004.