Democratic Gov. Andrew Cuomo criticized New York Mayor Bill de Blasio for being out of town when a massive blackout hit the Big Apple.

"Mayors are important. And situations like this come up, you know. And you have to be on-site. ... I think its important to be in a place where you can always respond, but look, everybody makes their own political judgment, and I'm not going to second-guess anyone either," Cuomo said on CNN.

De Blasio, a long-shot 2020 Democratic candidate for president, was campaigning in Waterloo, Iowa, when the power outage struck a wide swath of Manhattan in the early evening Saturday.

A few hours after the power outage hit, de Blasio told CNN he was not ready to make the call on whether he should return home. "I'm going to get more information in the next hour or so. And we'll adjust my schedule accordingly depending on what I hear," he said.

CNN's Ana Cabrera noted in her follow-up interview with Cuomo an hour later that de Blasio had decided to return to New York City.

A transformer fire is believed to have led to the power outages across Midtown and the Upper West Side. De Blasio said in his CNN interview that his first deputy and emergency management commissioner are on the ground to contend with the situation.

Cuomo said he was "directing the Department of Public Service to investigate and identify the exact cause of the outages to help prevent an incident of this magnitude from happening again" and noted Con Ed hopes to begin restoring power to affected customers by midnight.