"When I was in the wings, I saw it start to drizzle but I had no idea it was going this far," the 78-year-old "Mandy" singer told Cooper before serenading the TV personality with a snippet of his 1981 hit "I Made It Through the Rain."
"Maybe one of these days we can do this again and it won't rain," added Manilow, who also shared a video clip of the downpour on Instagram.
The all-star Homecoming Concert launched earlier in the day with performances by Journey, Carlos Santana, Jennifer Hudson and LL Cool J, among others, before being called off. Other artists on the lineup included Bruce Springsteen, Patti Smith, The Killers and Elvis Costello.
The event, produced by iconic record executive Clive Davis, was part of a week-long celebration of New York City's reopening, which consisted of live shows, free movie screenings, Restaurant Week, cultural activities and more.
CNN, the concert's exclusive broadcast partner, continued its coverage after the event was halted, including an interview by Cooper with scheduled performer Smith.
“A performer is there to not only inspire but to entertain the people,” she said. “There are things to talk about...," Smith added, emphasizing the crux of the continuing global and environmental pandemic. “These are important to acknowledge even in a night of celebration.”
She mentioned a number of the ongoing challenges in the world: fires, flooding, drought, famine, the earthquake in Haiti, fall of Kabul and the delta variant. “These are real things that are happening, so what are we celebrating?” Smith asked. The singer concluded that we are celebrating that “we as individuals have heart, resilience and the ability to make change.”
Smith also offered her thoughts about the storm in an Instagram post. "This is thunder lightning hurricane torrential rain to say nothing of a full moon The fields are bloody muddy," she captioned a photo of her talent badge from the concert. "The roof is leaking. The mind’s a tool and nature rules."
Watch CNN's video of Manilow reacting to his interrupted performance at the We Love NYC: The Homecoming Concert here, and hear Smith's interview with Cooper here.