About two hours after the game, won by the Ravens in a 34-31 thriller, officials revealed that an "abnormality" in the power system triggered an automatic shutdown, forcing backup systems to kick in. But they weren't sure what caused the initial problem.
New Orleans Mayor Mitch Landrieu called the power outage "an unfortunate moment in what has been an otherwise shining Super Bowl week for the city of New Orleans."
"In the coming days, I expect a full after-action report from all parties involved," he said.
Auxiliary power kept the playing field from going totally dark, but escalators stopped working, credit-card machines shut down, and the concourses were only illuminated by small banks of lights tied in to emergency service.
A joint statement from Entergy New Orleans, which provides power to the stadium, and Superdome operator SMG shed some light on the chain of events, which apparently started at the spot where Entergy feeds power into the stadium's lines. The problem occurred shortly after Beyonce put on a halftime show that featured extravagant lighting and video effects.
"A piece of equipment that is designed to monitor electrical load sensed an abnormality in the system," the statement said. "Once the issue was detected, the sensing equipment operated as designed and opened a breaker, causing power to be partially cut to the Superdome in order to isolate the issue. ... Entergy and SMG will continue to investigate the root cause of the abnormality."
The FBI quickly ruled out terrorism, and the New Orleans Fire Department dismissed reports that a fire might have been the cause.
Auxiliary power kept the playing field and concourses from going totally dark.
The failure occurred shortly after Jacoby Jones returned the opening kickoff of the second half for a 108-yard touchdown, the longest play in Super Bowl history and pushing the Ravens to a commanding lead. But when play resumed, the momentum totally changed.
The Niners scored two straight touchdowns and nearly pulled off a game-winning drive in the closing minutes.
"It really hurt us. We had lot of momentum," fullback Vonta Leach said. "We were rolling. That 35- or 40-minute wait, whatever it was, hurt our momentum as far as what we were trying to do. But we came out on top and that's all that matters."
Safety Ed Reed said some of his teammates were worried that the game would turn when the lights came back on.
"The bad part is we started talking about it," he said. "Some of the guys were saying, 'They're trying to kill our momentum.' I was like, 'There's two teams on the field.' But once we started talking about it, it happened. We talked it up."