Metro

Tot found healthy, unharmed after mom snatched infant son during supervised visit

Millions of sleeping New Yorkers got a jolt to the senses early yesterday when their cellphones rang with an Amber Alert about a baby boy who had been snatched from a child-welfare center in Harlem.

The rude awakening, which contained information about the suspect’s getaway car, was sent out shortly before 4 a.m., although some people reported getting it later in the day.

State police said the notification was the result of New York having joined the National Wireless Emergency Alert System on Dec. 31.

The system allows agencies to automatically send messages to newer-model smartphones in specified areas to warn people about emergencies there. But many people unaware of the program were jarred by the wake-up call, with some taking to Twitter to vent their anger.

“That amber alert at 4am scared the hell out of me. I thought my house was on fire,” wrote Twitter user @eduardomargarin.

Investigator Dan Craven of the state police Special Victims Unit, which issues Amber Alerts, said his office got “a few complaints,” but called it “a huge day for getting information about our program out there.”

He also said that people who don’t want the alerts can disable them by changing the settings on their cellphones.

The subject of the alert, 7-month-old Mario Danner, disappeared about 3 p.m. Tuesday during a supervised visit with his mom, Marina Lopez, 25, of Queens, who lost custody of the infant. The NYPD said Lopez — who has an extensive rap sheet and a history of mental problems — slipped out of a city facility at West 125th Street and Seventh Avenue and fled with the tot.

Cops said she and the boy were located yesterday in the Rockaways and that Mario appeared healthy and unharmed.

She left the 28th Precinct Station House in Harlem last night where she was charged with a felony count of custodial interference.

“Oh my God,” Lopez said as she led out of the precinct in handcuffs.

A police source said she and the boy were found based on a Crime Stoppers tip not tied to the Amber Alert but defended the decision to send out the alert.

“What if that was your child?” the source said.

kconley@nypost.com