Midtown residents, workers and tourists ran for their lives from homes and offices near a buckling building Tuesday — and now have no idea when they can return to the evacuated “frozen zone’’ around the site.

Nine buildings had to be suddenly cleared after 8 a.m. when crucial support columns began caving in the under-construction 37-story former Pfizer headquarters on East 42nd Street near Second Avenue — and City Hall would not say when anyone might be able to return to the area.

“Evacuate! Everybody out!’’ an employee at the Westin Hotel at 212 E. 42nd St. screamed over the loud speaker in the morning, sending customers and workers fleeing.

Three tourists from North Carolina said they were set to stay at the Westin for four days before their ocean cruise said they are now adrift without a place to bed down.

“I saw a breaking-news story pop up on Twitter,” said one of the trio, Nika Whitsett, 33. “I opened it and saw the streets. I said, ‘Oh, 42nd and Second. That’s where we’re headed!’ ”

The hotel sent an email to patrons Tuesday evening saying, “The latest update is the site of concern remains a safety risk, indicating the evacuation order will not be lifted anytime soon and will last well into the night, at the earliest.”

It was allowing them to go briely return to their rooms — but only to get their belongings.

A 22-year-old recent college grad who moved into an apartment on East 44th Street between Second and Third avenues just two days ago was trudging to her sister’s place across town — with two pieces of luggage and a bag of groceries in tow.

“I woke up because there were a ton of sirens and like police megaphones telling people to get out of the intersection,” said the young woman, who only gave her first name, Allie.

“I went to pack a bag, and then they started banging on the doors, and the Fire Department was saying that it might be like two weeks until we can get back — I’m really hoping that that’s some a very cautious estimate,” she said.

“I don’t even have a bed yet.’’

Dr. Stefan Mitra, who lives at East 41st Street and First Avenue, said he came home from a 24-hour shift at a Bronx neurosurgery unit to the mess.

“I slept an hour or two after my shift to be safe to drive, and then I came home thinking I’d be able to go home and get to sleep some more, but now I’m stuck,’’ Mitra said.

“Worst-case scenario, I probably will have to find a hotel somewhere,’’ the doctor said. “There’s no other option. I can’t just wait forever.”

Sitting on a nearby flower bed was Mercy Muriungi, 52, who is based in Texas — but was in her part-time East 44th Street apartment at 9 a.m. when she got the notification demanding she evacuate.

“I just grabbed my purse. I thought this was gonna be more like a drill,” Muriungi said.

“I haven’t taken out the trash, I left all my medicine in there. I had to walk over to the pharmacy to see if they would give me some medicine for a day or two,’’ she said.

A worker at the buckling building said he was on the fourth floor when “somebody called my boss on the radio.

He told everybody to leave the building. He was talking fast: ‘There is a problem, everybody get out, get out, you have to leave the building.’ He was waving his hand,” the hardhat said.

“I know it could not be something good.”

City Hall officials did respond to questions about how many people were displaced by the emergency situation or when they might be able to get back to their lives.

The Mamdani administration only said a team of experts had gone into the building by the afternoon and, “We have determined that the contractors on-site can move forward with the installation of temporary shoring to stabilize the building.

“This emergency shoring is a measure to stabilize the building, and additional stabilization work will be done throughout the evening and coming days.”

The response wasn’t enough for those displaced.

“I don’t know what I’m supposed to do,” a resident at 230 44nd St. said. “I guess I’ll stay at my buddy’s place downtown tonight.”

Carlos Mendes, 29, of São Paulo, Brazil, was in town for business and staying at the Westin.

“I’ve spent the last few hours trying to find another hotel, but everything nearby is expensive or already booked, and I’m supposed to be here through the end of the week for work,’’ Mendes said.

“It’s frustrating because you understand they’re trying to keep everyone safe, but you’re also just standing here with no real answers, wondering where you’re going to sleep tonight and whether you’ll ever get your suitcase back.”

Also among those out on the street were workers at Israel’s Consulate in New York.

“All consulate staff were evacuated safely,” Consul General Ofir Akunis said in a statement. “I have instructed the team to examine alternative arrangements to resume normal conditions as quickly as possible.”

-Additional reporting by Haley Brown and Jen Bain