After nearly 70 years on the air and on the brink, Berkeley-based KPFA-FM could be facing the end of its run as a pioneering, proudly left-wing radio outlet.

There is some irony in the fact that after labor disputes, strikes and other controversies in the years since its founding in 1949, the station whose motto is “Vigilant as Always” faces demise because of the financial woes of a radio station in New York City.

A New York judge has ruled that KPFA’s sister station, WBAI, is liable for $1.8 million in back rent for its transmission tower atop the Empire State Building. The judge also ruled that the landlord, Empire State Realty Trust, may pursue seizure of the assets of WBAI’s parent, Pacifica Foundation, of which KPFA is the flagship station.

Pacifica does not have $1.8 million, and as soon as Monday, Empire State could begin procedures to seize the company’s bank accounts along with the sprawling downtown Berkeley complex owned by Pacifica and housing KPFA. Empire State has not indicated that it will pursue a seizure, but it has filed with the state to do so and the 30-day waiting period ends Monday. Pacifica management is hoping its landlord will agree to leave the property alone while a solution is explored. Empire State Realty Trust did not respond to a request for comment.

“Until we can get a written agreement from Empire State, we are at their mercy,” said Bill Crosier, interim executive director of the Pacifica Foundation, in an interview Thursday on the KPFA program “Up Front.”

“The imminent danger is a judgment against KPFA’s parent company, the Pacifica Foundation, that could drain KPFA of its operating funds and take the Bay Area’s only truly progressive radio station off the air,” read a Tuesday posting, signed by KPFA management and attributed to General Manager Quincy McCoy, on the KPFA website..

Crosier said he and his staff had recommended that Pacifica file for Chapter 11 bankruptcy in order to stave off the seizure while Pacifica reorganizes. But the notoriously acrimonious Pacifica national board has thus far rejected that strategy and has not authorized staff to begin bankruptcy preparations.

“The governance structure of Pacifica, our historic culture of the usual political infighting has led to disagreement and paralysis,” McCoy wrote. “Unless action is taken pretty immediately we may cease to exist.”

Bankruptcies are common in commercial radio these days. The nation’s largest radio conglomerate, iHeartMedia, is facing Chapter 11 any day now, buried under a $15 billion debt. Its rival, Cumulus Media, which owns KGO-AM radio, among other Bay Area stations, filed for Chapter 11 in November, with a $2.4 billion debt.

But bankruptcy is rare for a public radio station, and a Chapter 11 filing would be the first in the long, death-defying history of listener-funded Pacifica, which operates stations in Berkeley, Los Angeles, New York, and Houston and Washington, D.C.

“There is a stigma to bankruptcy,” Crosier said in an earlier on-air interview. There is also a cost of up to $1 million, but a Chapter 11 filing would halt the action by Empire State.

The New York tower lease, which dates to 2005, costs about $60,000 per month and runs through 2020 with annual increases of 9 percent. In bankruptcy court, the judgment could be reduced and increases capped, Crosier told the host. Pacifica could also be put into receivership.

“We owe them a lot of money, and we have to pay it, and we plan to pay it,” said Crosier. “We hope they will be patient while we figure out how to pay them.”

A second option — one favored by the board but opposed by management — is to take out a $2 million loan to pay off the judgment. Pacifica has assets of approximately $10 million in real estate and licenses worth $100 million. But cash flow is negative. Pacifica is $8 million in debt and has operated at a deficit for 15 consecutive years. It also has accrued three years in unpaid pension obligations.

“It has been a toxic brew of bad management, poor internal political mechanisms for selecting the boards and exclusion of listener participation that has led to this low point,” said former general manager and retired national correspondent Larry Bensky.

Another option is to sell assets or swap signals with another station in order to raise capital. This could weaken KPFA, which is probably the most solvent of the five stations, thanks to the generosity of its listeners who support fund drives.

“It’s been a consistent progressive voice and bulletin board for just short of 70 years,” said Ben Fong-Torres, who writes the Radio Waves column for The Chronicle. “Although it’s never gotten sizable ratings, it’s got a passionate audience.”

According to its unaudited financial statement, KPFA took in $3,337,510 in income against operating expenses of $2,964,973 in 2016, the most recent year available. KPFA business manager Maria Negret reports that the holiday 2017 pledge drive raised $511,000, well over the goal of $450,000.

But Bensky counters that those numbers hide the fact that listener support has been eroding over the years. To make it worse, because of its governance structure, KPFA has to support its sister stations, as made evident by the situation in New York.

“KPFA has been bled dry to pay for the other stations, especially New York, which has been sucking away money for years,” Bensky said. “It has no listeners.”

Negret said Pacifica should not be saddled with an additional loan, which WBAI has no ability to pay.

“Many of us feel that Chapter 11 is the best way to go. It would give us a chance to breathe and re-organize the network,” she said in an email.

“All I can be sure of is that KPFA is strong. We are here, ready to keep going,” she wrote. “In this national political climate, we need KPFA and Pacifica more than ever before.”

KPFA went on the air at 3 p.m. April 15, 1949, when a group of Berkeley anarchic pacifists led by Lewis Hill commandeered an unused frequency. Because almost nobody had heard of FM, they distributed shoebox-size tube radios with the dial set to 94.1 to potential listeners. Hill was seen as too controlling and was dumped by his own board in a political coup in 1953. A year later, Hill staged his own coup, reclaimed power and drove out the board.

It has been that way ever since, only with additional stations and a national governing board atop the KPFA board, increasing the ever-present potential of infighting.

This was made clear at the 50th anniversary in 1999, marked by Pacifica’s firing of popular KPFA general manager Nicole Sawaya. That was followed by the firing of Bensky, who had broken a company gag rule for speaking on air against Sawaya’s firing.

Some 10,000 people took to the streets in protest. A planned 50th anniversary celebration was canceled, people were arrested and the station was seized by Pacifica, which aired syndicated programming for about a month. The coup was overcome, but some say the spirit was lost, along with Bensky’s position as national affairs correspondent.

“There has been diminished and now nonexistent national programming since then,” said Bensky, who had to sue Pacifica to get back his job, which he held until 2007.

Ten years later, he sees the station as “a ghost of its former self and a sad remnant and relic of what once was. KPFA is much weaker, and the Pacifica national network is nonexistent.”

Crosier said the board “spends too much time fighting and not enough trying to get listeners.” He has been warned that some board members plan to sue the board if it caves to Empire State.

But the music shows continue in the evenings and weekends, year after year and decade after decade. There is “Dead to the World,” formerly “The Grateful Dead Hour,” hosted by Tim Lynch on Wednesdays at 8 p.m., and “The Bonnie Simmons Show” at 8 p.m. Thursdays followed by Derk Richardson with “The Hear and Now” at 10 p.m.

Saturday mornings bring “Blues by the Bay,” with Tom Mazzolini. Sunday afternoons have the doubleheader of “America’s Back 40,” hosted by Mary Tilson, and “Panhandle Country” with Tom Diamant.

“The program hosts have given us as close to free-form radio as we can get on terrestrial radio,” said Fong-Torres.

Listen now. By next weekend they could all be off the air, though legal delays are a possibility.

Still, General Manager McCoy is acting as if the locks will be changed on Monday. According to a staff member, he sent employees an email warning, “We will cease broadcasting because we will be unable to operate the station. At that point, our building and our bank account will no longer be under our control.”

Sam Whiting is a San Francisco Chronicle staff writer. Email: swhiting@sfchronicle.com Instagram: @sfchronicle_art