While watching New Orleans Councilman James Gray's growing exasperation as he grilled Sewerage & Water Board General Superintendent Joe Becker over Saturday's surprise flood, I thought I had come up with a pretty good line to describe the exchange: Maybe Gray should have gone to dental school instead of law school, because this is like drilling teeth.

Then Gray one-upped me. He admitted that he entered the election-season special meeting wondering if the council might be piling on, and even confessed that he had some sympathy for Cedric Grant, the S&WB executive director who first said the system operated at full capacity and then admitted that it did not. But all that evaporated as Gray struggled to get straight answers from Becker.

"I thought we were on a witch hunt," Gray said, "but we have found witches."

City and water board officials had initially claimed the system had done all it could, and attributed the inundation of roads, homes and businesses, as well as the slow drainage process, to a localized but intense rainstorm that dropped more than nine inches in one spot. Grant also rankled some residents by linking the frequency of heavy rain events lately to climate change, a comment that Mayor Mitch Landrieu later called tone deaf and out of context.

But Monday, two days after the flood, Becker said that seven of the system's 121 pumps had been out of service during the storm. By Tuesday that number had grown to 14 , and water board officials acknowledged for the first time that there had been some issues with power generation to run the pumps. Just before the council convened, Grant issued a statement saying that his earlier assurances had been wrong and that some staff members had not been forthright with him about conditions on the ground. Rather than be a distraction, he said, he'd tendered his resignation, effective some time this fall.

Grant's admission that the board had put out bad information just upped the temperature in the packed council chamber, where angry residents frequently shouted and booed.

Some of the testimony from various government officials wasn't particularly damning; several explained, for example, how turning on the giant pumps to Lake Pontchartrain that were built after Hurricane Katrina would not have helped.

But some was. The head of the city's homeland security office said he was not aware that there were issues with pumps and electricity. Officials clearly didn't satisfy council concerns as to why the citizen alert went out relatively late, or why they couldn't do more to block or steer traffic away from flooded streets. An official with the Army Corps of Engineers acknowledged that construction on drainage improvements at the Peoples Avenue Canal in Gentilly may have exacerbated the situation nearby.

Nothing, though, topped Becker's exchanges with both Gray and City Council President Jason Williams. Williams asked Becker why he'd said that all the pumps were working at full capacity, to which Becker responded that all the pump stations were at full capacity.

"This is already bad," Williams responded. "There's no reason to make it any worse"

Gray repeatedly ask Becker to specify that how hobbled a particular pump station in Lakeview was, and even suggested that Becker help him out if he wasn't phrasing his questions to elicit the information he was obviously seeking. It still took him repeated passes get Becker to say that, between pumps being out of service and electrical challenges, the station was operating for a while at just 52 percent.

By the end, Gray was wearing his frustration on his sleeve, and basically said he'd lost confidence in Becker going forward.

Apparently Landrieu agreed. Even before the citizen-input portion of the meeting ended, the mayor announced that Public Works Director Mark Jernigan would leave City Hall, and said he'd ask the water board, which he leads as president, to dismiss both communications director Lisa Martin and Becker.

"It's inaccurate to suggest the system was operating at its maximum abilities," Landrieu said. "This was not true and this is unacceptable."

Follow Stephanie Grace on Twitter, @stephgracela.