New Orleans — The Ravens were rolling, Beyoncé had just put on a stunning halftime show and then the unprecedented happened: The lights went out in the Mercedes-Benz Superdome in the third quarter of Super Bowl XLVII.

Usually a beacon on the New Orleans skyline, the Superdome was bathed in darkness when the majority of lights flickered out at 7:36 p.m., shortly after Jacoby Jones returned the opening kickoff of the second half for a touchdown. There was 13:22 left in the quarter and the Baltimore Ravens led the San Francisco 49ers 28-6.

The power was off inside the stadium for 34 minutes. The lights started to come back on at 8:02 p.m. and play resumed at 8:10 p.m.

The exterior lights flickered on at about 8:20 p.m. and the Superdome took back its place in the New Orleans skyline.

“The power outage was an unfortunate moment in what has been an otherwise shining Super Bowl week for the City of New Orleans,” New Orleans Mayor Mitch Landrieu said in a statement issued Sunday night. ”In the coming days, I expect a full after-action report from all parties involved. For us, the Super Bowl isn’t over until the last visitor leaves town, so we’re focused on continuing to show our visitors a good time.”

Emergency lights went on shortly after the first lights went out, but play was immediately halted. The teams remained on the field with players stretching and trying to stay warmed up, including the Ravens’ Joe Flacco and Ed Reed. Cheerleaders kept going through their routines and a public address announcement asked fans to stay in their seats.

Officials gathered on the field and appeared to be talking to stadium personnel, but when it became clear it would not be a brief outage, everyone left the field with some players staying on the sideline.

According to a joint statement late Sunday night from Entergy and SMG, the management company of the Superdome, the outage was caused when a piece of equipment designed to monitor the electrical load sensed an abnormality in the system.

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, according to the statement.

Backup generators kicked in immediately as designed. Entergy and SMG subsequently coordinated start-up procedures, ensuring that full power was safely restored to the Superdome, the statement says.

The fault-sensing equipment activated where the Superdome equipment intersects with Entergy’s feed into the facility, according to the statement.

There were no additional issues detected, but Entergy and SMG said they will continue to investigate the cause of the abnormality.

Eric Eagen, a Superdome spokesman, sent out a statement shortly after power was restored.

“Power has been restored. We sincerely apologize for the incident,” he said.

Fans had mixed feelings about the power outage.

Jeff Devin, 53, a Tampa Bay Buccaneers fan from Tampa, Fla., said he was sitting in the upper level of the stadium when the lights went out.

“It was a surprise; however, I thought it was part of the show,” Devin said.

He said he did become concerned about what was happening outside the stadium when the Superdome went dark.

Devin said he felt the communication from Superdome and NFL officials was not enough to ease concerned fans such as himself.

“Nobody announced anything,” Devin said. “Announce. Give us a little clue. My greatest concern was that there was no communication channel.”

Darren Fruman, 39, and Danny Glazer, 38, Ravens fans from Baltimore, said they were sitting in section 302 when the lights went out.

Fruman and Glazer said they were not too concerned about safety and felt Super Bowl officials gave the public enough notice about what was happening.

“They could actually still play,” Glazer said.