New Orleans Mayor Mitch Landrieu speaks during a news conference at City Hall in New Orleans, Tuesday, Feb. 5, 2013. Landrieu said that the outage won't hurt the city's chances of hosting another Super Bowl and he joked that the game got better after the blackout. AP Photo/Jonathan Bachman Charles Rice, president and CEO of Entergy New Orleans, talks about the power outage during the Super Bowl, at a news conference at City Hall in New Orleans, Tuesday, Feb. 5, 2013. Superdome manager Doug Thornton, left, and Charles Rice, president and CEO of Entergy New Orleans, talk about the power outage during the Super Bowl, at a news conference at City Hall in New Orleans, Tuesday, Feb. 5, 2013. NEW ORLEANS (AP) - New Orleans' mayor defended his city days after a power outage plunged the Super Bowl into 34 minutes of darkness, while authorities still baffled by the cause announced they were bringing in a consultant to help investigate. The outage that embarrassed New Orleans as it sought to showcase its rebound from the devastation of Hurricane Katrina happened despite hundreds of thousands of dollars of improvements to decaying utility lines, documents show. Mayor Mitch Landrieu sought to put an upbeat spin on the matter at a news conference Tuesday, saying the city's performance as host was near flawless despite the lights-out episode. "The 34 minutes of darkness will never overshadow or outshine the city of New Orleans and how we performed this Super Bowl week," Landrieu said. He also said the outage won't pull the plug on city plans to bid for an 11th Super Bowl in 2018. It last hosted a Super Bowl in 2002, three years before Katrina swamped the city. Concerned the Superdome might not be able to handle the energy needed for its first Super Bowl since Katrina, officials spent hundreds of thousands of dollars on upgrades to decayed utility lines, according to the documents obtained by The Associated Press. The improvements apparently weren't enough, however, to prevent the glaring third quarter outage that was as much talked about as the Baltimore Ravens' 34-31 victory over the San Francisco 49ers. Still, NFL Commissioner Roger Goodell said the city did a terrific job hosting this time. "I fully expect that we will be back here for Super Bowls," he said. On Tuesday, Superdome officials and the power provider Entergy New Orleans said they had failed to find a cause for the outage. They added they would hire a consultant to analyze their data. It wasn't clear how long an investigation would take. "We thought it was important to get another party looking at this to make sure we were looking at everything that we need to," Entergy spokesman Chanel Lagarde said. The documents also show that Entergy expressed concern about the reliability of the service before the Super Bowl. Superdome commission records show a $513,250 contract to replace feeder cables was awarded to Louisiana-based Allstar Electric. Arthur Westbrook, Allstar's project manager for the job, referred all questions to the management company. A lawyer for the LSED, Larry Roedel, said a preliminary investigation found the replacement work in December did not appear to have caused Sunday's outage. And meters showed the 76,000-seat stadium was drawing no more electricity than it does during a typical New Orleans Saints game, according to Doug Thornton, vice president for the Superdome's management company, SMG He also ruled out Beyonce's halftime performance. Officials with the utility and the Superdome were quick to note that an NFL game, the Sugar Bowl and the New Orleans Bowl also were played there in recent weeks. It remained unclear what the abnormality was or why it occurred.