Amtrak service between New York City and Croton-on-Hudson in Westchester County remained suspended Monday afternoon after officials said a parking garage in Midtown Manhattan had structural issues that potentially endangered tracks below it.

Amtrak had no estimate for normal service restoration as of shortly before 1 p.m. Monday, according to a spokesperson for the railroad company, and has not issued any new service alerts for the corridor since then.

In a service alert issued at 8:40 p.m. Sunday, Amtrak said it was temporarily suspending service between Moynihan Train Hall at Penn Station and the Croton-Harmon station due to "safety concerns" related to structural issues at a privately owned building in the city, above the Empire Line tracks that run to Albany.

As an alternative, Amtrak directed customers to take Metro-North between Grand Central Terminal and Croton-Harmon, and said Amtrak tickets would be "cross-honored" by Metro-North.

Late on Sunday afternoon, Mayor Eric Adams said in a series of posts on X that engineers with the city's buildings department had begun assessing the situation at the parking garage immediately after the city learned of the problems there.

"Emergency work orders were quickly issued so the parking garage owners could begin addressing the issue," Adams said.

The garage is located on W. 51st street between 10th and 11th avenues, in Hell’s Kitchen. It’s part of the Hudsonview Terrace apartment complex along 10th Avenue, which is owned by New York-based Lineage Properties.

A person who answered the phone at the company’s office and identified themselves as “management” declined to comment and hung up after a reporter identified himself and asked about the garage issues.

The city Department of Buildings told Gothamist the issues were “localized to the garage only,” and that an engineer for the property owner called 911 to report them last Friday. DOB and Amtrak engineers then went to the scene and found two holes “measuring in inches” on the garage’s entrance ramp and a ramp to the lower level, according to the department.

The DOB issued a vacate order at the garage, and the engineers determined they could install “overhead protection” above the tracks and run trains as normal while the garage owners repaired the section above the train tunnel’s roof, a DOB spokesperson said.

But early on Sunday morning, the spokesperson said, Amtrak workers observed “additional structural issues” at the roof, and DOB engineers were called back to the garage. There, they found “additional structural deficits including cracked and deteriorated steel beams,” per the spokesperson.

One of the holes inspectors found in a ramp in the parking garage looks straight down into the Amtrak tunnel.

On Monday, the DOB was waiting for a repair plan from the property owner that would include a timetable for the work, according to the department.

Under city law, the owners of every parking structure in Manhattan south of Central Park and on the Upper West Side are required to submit a detailed inspection report by the end of this year. So far, less than 10% of the 1,023 garages in those zones have submitted a report, city data shows. All other garages in the city are required to submit a less comprehensive report completed by a licensed engineer by August 2024, Gothamist first reported last month.

The owner of the garage at Hudsonview Terrace had not yet submitted the report, the DOB said Monday. The new inspection rules were established after a partial collapse of a parking garage downtown killed the garage’s longtime manager and injured several others.

Jason Damiano, a senior structural engineer at RAND Engineering and Architecture, said the ongoing episode highlights the importance of the city’s inspection rules.

One of the holes inspectors found in a ramp in the parking garage looks straight down into the Amtrak tunnel.

“Every garage, in theory, is supposed to have eyes on it by August so hopefully this potential for collapse is averted,” said Damiano, one of 85 engineers licensed to complete parking garage inspections under the city’s law.

Damiano, who did not inspect the garage in question and was commenting generally, said clear structural problems in a parking garage can have devastating consequences for an entire building because slabs — the concrete floors cars park on — often brace the columns that support the structure above.

“If slabs are no longer able to handle these loads, a localized issue is not necessarily just a localized issue,” he said. “That’s a worst-case scenario.”

Last month, service on Amtrak's Empire Line and Metro-North's Hudson Line was temporarily suspended because of a rain-induced mudslide in Westchester County that left major debris on the tracks. Service was largely restored by the next day — a Monday — after workers cleared much of the debris.

This story has been updated with additional information.