A longtime U.S. postal carrier was found dead in her mail truck in Woodland Hills on Friday afternoon amid blistering summer temperatures, authorities confirmed Monday.

Peggy Frank, 63, of North Hills was found unresponsive while seated in a postal vehicle in the 4800 block of Calderon Road by a co-worker or bystander, said Ed Winter of the Los Angeles County Department of Medical Examiner-Coroner’s office.

Paramedics attempted to revive her without success, Winter said. Frank was pronounced dead at 3:35 p.m. Friday.

UPDATE: Federal investigators launch probe into Woodland Hills mail carrier’s death on 117-degree day

Temperatures soared to 117 degrees in the Woodland Hills area on Friday, surpassing the record of 106 degrees for that day, July 6, that was set in 1976. (The National Weather Service has kept records there since 1949, according to Keily Delerme, a NWS meteorologist.)

But Winter could not say Monday whether the heat was a factor in Frank’s death.

While her autopsy had been completed, the cause of death was deferred pending additional tests, Winter said. She also had some type of medical history that Winter declined to specify until the final cause of death is determined.

“We want to express our thoughts and prayers for the employee’s family at this difficult time,” said Evelina Ramirez, a spokesperson with the U.S. Postal Service.

She noted that carriers deliver mail in “all kinds of weather, including high temperatures.”

“Safety is our top priority for all of our employees,” Ramirez said. “The Postal Service strives to ensure that they have the tools and training to do so safely.”

Carriers are reminded daily to stay hydrated, wear appropriate clothing, such as hats, and get into the shade whenever and as much as possible, she said.

“The most important thing is to make sure they have water and ice for their entire route,” Ramirez said.

Employees at the Woodland Hills Post Office remembered Frank, a dog lover who had some 28 years working at the post office, as always upbeat and positive despite her health challenges.

“She was a sweetheart – always happy, even when she wasn’t feeling good,” said co-worker Cindy Pritchard.

Frank had recently returned from medical leave, according to colleagues.

Co-worker Joni Hogan Salvatore, who started working at the Woodland Hills Post Office before Frank, called her colleague “amazing” and “a very hard worker.”

“None of us are 20 (years old) anymore; it’s a hard job,” Salvatore said. “It’s a super-hard job, but she always had something nice to say. Never was a complainer or anything. She was just a really good person.”

Salvatore said that when it’s 100 degrees outside, it can be 10-15 degrees hotter inside the mail trucks, which do not have air conditioning.

“They make us lock them and seal them for safety of the mail, but it’s horrible in there,” she said.

The National Weather Service had issued an excessive heat warning on Friday for the region.

A spokesman for the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA), which has jurisdiction over federal employees, could not be reached late Monday for comment.

In the fall of 2014, an administrative law judge upheld a willful citation to a U.S. Postal Service station in Independence, Mo., by the federal OSHA after a mail carrier died in July 2012, according to media reports.

The mail carrier had collapsed while working his route and died as a result of his exposure to excessive heat, according to an OSHA investigation.

That investigation found that the Postal Service “did not have procedures in place to address worker concerns during times of excessive heat,” according to the administrative agency. A willful violation is one that is committed with intentional, knowing or voluntary disregard for the law’s requirements or with plain indifference to worker or safety health.

The Postal Service was required to pay a penalty of $70,000 in that case, according to the news site Fox4KC.com.

In October of 2016, OSHA cited the Postal Service after two Des Moines, Iowa, workers suffered heat-related illness while delivering mail that past summer. The agency found that the two mail carriers, one of whom was told to continue walking her route despite feeling ill, were exposed to excessive heat.

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