Jennifer Lopez returned to Madison Square Garden in New York City on Monday night for a makeup concert after her Saturday show at the massive arena was evacuated and cancelled following a city-wide blackout that plunged the Big Apple into darkness.

The celebrated songstress triumphantly took the stage once again, and this time managed to perform more than just her first two songs without the lights going out and the 20,000 seat arena getting cleared out.

ET spoke with Lopez at her show on Monday -- which was one stop on her It's My Party Tour -- where she reflected on the unexpected power outage over the weekend, and explained how it wasn't the first time she's dealt with that sort of challenge.

"This happened to me one time at the Staples Center. I was performing with Pitbull, we were closing [a show] and all the lights went out," she recalled. "We had the same thing, a power outage, and it came on seven minutes later and we kept going."

"So, when this happened, I was like, 'OK, let's just wait a second, it will come back on and then we'll just keep going.' [But] then, you know, people were yelling, 'We've got to evacuate,' and you know, it was a big dramatic thing," she added. "Luckily everybody got out safe."

When Lopez's show was forced to end early on Saturday, the event and the tour were insured for unforeseeable events such as blackouts, meaning the singer wasn't legally or financially obligated to make good on the concert. However, Lopez says she felt she owed it to her fans to come through.

"They were like, 'You don't have to do the show, you know, insurance will cover everything -- including you, including the fans, and everything will be fine.' But I just felt like everybody came out for this special celebration. The crowd was so electric that night, even just for the first 15 minutes that they got to see," Lopez explained. "So I was like, 'I just can't leave it like that, I don't want to leave it like that. They like the experience, that's what they came for and I want to give it to them.'"

On Monday, Lopez hit No. 1 on the Billboard Dance Club Songs chart for the 17th time with the opening track of her show, "Medicine" with French Montana. And when she took the stage that night, the performer said that the energy in the audience and the arena was "off the charts."

"There was something special in the air, I think," she added. "Because we got interrupted and it looked like it wasn't going to happen, and it could have [possibly] not happened. And then to be back here, and for me to be able to do this with those same people, it was just electric."

Following the blackout, Lopez took to her YouTube page for a new chapter in her ongoing Tour Diary which detailed the outage, the cancellation, and the backstage goings-on that followed.

One guest who was in the audience on Saturday and again on Monday for the makeup show was CBS This Morning anchor Gayle King

Speaking with ET, King opened up about what it was like to see the blackout at Lopez's concert unfold first-hand from the point of view of the audience.

"I'm sitting with Benny Medina, who's her manager, and I'm at the sound board and all of a sudden it goes dark," King recalled. "So I'm thinking, actually, 'It's a part of the show,' and Benny goes, 'That is not supposed to happen.'"

"I knew that we had had a blackout in other parts of the city -- I was surprised that the lights were even on in Madison Square Garden, so I thought, 'OK, this is good, this is good.' But [Medina] became very concerned. He began talking with the technical crew, then it was very clear that this was a blackout," she added.

According to the news anchor, Lopez later took the stage, without a working mic, in an effort to calm and reassure the crowd. And even though she couldn't be heard, the audience was able to see her efforts to make the best of the situation.

"I love the video that she did after," King said of an Instagram video Lopez posted after the evacuation, in which she said she was "devastated and heartbroken" after having to cancel the performance. "You could see she was very upset, because if there's one thing she doesn't like to do, it's letting people down."

For more on the blackout that swept Manhattan over the weekend and forced the cancellation of Lopez's show, check out the video below. Tune into Entertainment Tonight on Tuesday to hear more from the singer on her epic tour and upcoming birthday!

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