Last May, Paula Fraser, BART’s assistant chief transportation officer, sent an email to Jerry Lockett, a manager, with photos showing the downtown Berkeley station during a blackout.

“Here is what (Berkeley) Station looked like when we loss [sic] PG&E power. No emergency lighting,” she wrote.

The dark, grainy photos, which were printed and then scanned in response to a public records request by this news group, show a pool of light streaming in from a skylight in the below-ground station, illuminating a staircase that leads to the blackened platform below. Those records show the Berkeley station as just one in a string of documented failures of the emergency lighting system at a minimum of five stations over the past year.

The records raise questions about why the agency didn’t act to complete an audit of its backup power systems until the issue was brought to light by BART patron Kathleen Lassle, a Walnut Creek resident and an engineer by trade. She was terrified when she had to walk out of a train at the Montgomery Street station on April 21, when a fire at a PG&E substation knocked out power to a large swath of San Francisco and darkened the station. With no emergency lighting, patrons were left to illuminate their paths with only the glow of their cellphone screens.

She called the revelations “troubling but not surprising.”

Emergency lights, powered by a network of batteries, are supposed to turn on immediately in the event of an outage, and BART is required by state fire and building codes to provide at least 90 minutes of illumination to help passengers and employees navigate stairwells, traverse corridors and find exits. But that didn’t happen at the Montgomery station that morning in April or at the Berkeley station last May.

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26-story housing highrise eyed in downtown San Jose And it didn’t happen less than a week after the Montgomery outage, on April 27, when a downed pole cut off power to the Richmond station. Paul Oversier, BART’s assistant general manager of operations, said at the time it wasn’t until the lights again failed to activate at the Richmond station that BART suspected the problem could be districtwide.

“The fact both stations experienced a failure in the emergency backup system was extremely troubling,” Oversier said in a statement last week. “We immediately launched an investigation, and ordered a robust districtwide inspection of all related systems.”

However, newly released records show BART was aware the emergency lighting failed at the Richmond station as early as November — though it’s unclear whether it was ever repaired at the time. Representatives for the agency did not return requests for comment about what corrective actions were taken at either the Richmond or Berkeley stations, and a request for documents detailing such actions did not return any records.

The Berkeley station had last been inspected on April 4, 2016, a little more than a month before Fraser shared photos of the darkened station, on May 18.

At the time, Michael Lemon, BART’s reliability manager, chimed in on an email thread, “That’s bad, we need to address prior to having an incident that results in a patron being injured.”

Lori Lovett, BART’s assistant chief engineering officer, responded, asking that “high-priority stations” be included in the district’s capital needs inventory, which it was in the process of updating. The inventory, released in November 2016, includes $9.5 million for new emergency lighting systems at the Berkeley, Lake Merritt and 12th Street stations.

BART also identified problems with the emergency lighting systems at the Pleasant Hill and Union City stations in November and at the West Oakland station in July last year. In the case of the Union City station, employees were still emailing each other in March to check whether a faulty fan cooling the lighting system had ever been replaced.

In the case of West Oakland, a maintenance worker checked the system June 4, noting that new batteries had been installed in 2015 and all the emergency lights were charged and in “proper working condition.”

But, less than two months later, on July 28, 2016, Tim Cochrane, BART’s electrical section manager, asked for guidance on which kind of batteries to buy for the station’s emergency lighting system, saying he would be replacing both battery banks completely.

Like many on the board, Director Joel Keller, who chairs the board’s operations and safety subcommittee, said safety should be the agency’s chief concern.

“It’s troubling that corrective action was not taken as soon as the emergency lighting problem was identified,” he said.

And while board President Rebecca Saltzman called the failures “unacceptable,” she said the only thing to do now is focus on solutions. The agency last week completed an audit of its emergency lighting systems throughout the district and ordered new batteries for 14 of its 46 stations.

It is also addressing deficiencies in record-keeping, maintenance procedures and policies governing accountability and documentation, including more frequent inspections, checks of the systems by two supervisors and unannounced, on-site audits. And, as part of the $3.5 billion bond measure voters approved in November, BART plans to spend some $27 million upgrading or replacing its emergency lighting systems.