(CNN) -- Worries about the Superdome's wiring led to an order for hundreds of thousands of dollars in "emergency" electrical repairs in the months leading up to Sunday's Super Bowl, documents show.
Although there is no proof the problems were behind the partial blackout at the multi-million-dollar extravaganza, they are among the latest details to emerge in the mystery surrounding the embarrassing snafu.
Power company Entergy upgraded service at the Superdome, but had "concern about reliability" of service from its connection point to the dome, according to a memo dated October 15, 2012.
An attorney for the Superdome's managers provided the documents to CNN.
The new information includes memos and meeting minutes prepared for the Louisiana Stadium and Exposition District, a state agency that oversees a group of facilities including the Superdome.
An October LSED memo mentions that a firm was hired to test the secondary electric feeders at the dome. It was "determined that the feeders had some decay and had a chance of failure."
Those same tests led an engineering firm to conclude that "the Superdome's main and only electrical feed, based upon test results ... are not sufficiently reliable to support the high profile event schedule."
The board categorized these repairs as an "emergency," according to minutes from an LSED meeting in October.
By that point, the board had already approved spending up to $700,000 to replace parallel electrical power feeds.
In November, the board was updated about "the replacement of the electrical feeders that connect the Superdome to the Entergy power vault." The board approved spending $513,250 on what the minutes referred to as the "Emergency Feeder Repair Project."
The company confirmed it completed some upgrades to electrical delivery systems to the facility on December 21, but Entergy has said that may have had nothing to do with Sunday night's problem. The dome hosted a few major events after that work was carried out, including the Sugar Bowl.
Entergy says a piece of equipment designed to monitor electrical load sensed was tripped by an "abnormality" and partially cut power to the stadium, as designed. The switch gear is designed to cut some power so as to isolate the problem and prevent a larger outage.
LSED, Entergy and the company that manages the Superdome, SMG, said in a joint statement Tuesday that they have hired an independent third party to investigate the cause of the blackout.
Entergy will continue to conduct its own investigation.
The 35-minute electrical outage during the Super Bowl set off a storm of social media amusement among viewers and inspired advertising tweets with blackout twists.
Carmaker Audi took a swipe at its competitor, tweeting that it was sending "LED lights" over to the dome, which is officially named the Mercedes-Benz Superdome.
But for the picturesque Super Bowl host city -- perpetually concerned with its reputation, especially since Hurricane Katrina -- the power failure broadcast to the world was a huge embarrassment.
Mayor Mitch Landrieu promised that night there would be answers soon.
The council member who heads New Orleans' utility committee, Cynthia Hedge-Morrell, hopes some will be forthcoming at the meeting this week.
"I am extremely disappointed in the power failure at the Superdome during last night's Super Bowl game," she said in a statement Monday.
The NFL has said the incident will not likely diminish the city's chances of hosting another big game.
The general consensus on social media appeared to be that Beyonce's high-wattage half-time performance was mostly likely to blame for the blackout.
NFL Commissioner Roger Goodell countered the virtual chatter, saying, "There is no indication at all that this was caused by the halftime show, absolutely none."
The blackout triggered calls by industry leaders for the building of a nationwide smart power grid, which could reroute electricity seamlessly in such cases.
This would avoid such public displays of momentary weaknesses in the system, said Andres Carvallo, former chief technology officer at Austin Energy, where he says he built the nation's first smart grid.
On Monday, CBS aired video shot from inside a stadium control room as the outage occurred.
"All right, we lost lights," says a man as the room darkens.
CNN's Brian Todd, Dugald McConnell, Lindsey Knight, Tom Watkins, Tina Burnside, Ben Brumfield and Chelsea Carter contributed to this report