The incident happened on Tuesday afternoon in Pleasanton.
A video from a concerned neighbor shows the dog in distress.
Neighbors called for help and police responded, but they were too late.
PREVIOUS: Dog left on apartment balcony in Pleasanton dies from heat stroke
Dog left on apartment balcony in Pleasanton dies from heat stroke
The dog's owner contacted ABC7's Lauren Martinez on Thursday and they spoke on the phone. He didn't feel comfortable going on camera but shared a statement to ABC7.
"I am heartbroken by the recent loss of my dear Zene [Nene]. This unbelievable tragedy struck unexpectedly, stemming from her learned behavior of letting herself onto the balcony for fresh air and sunbathing-a skill I taught her to help her move around freely and assumed no danger. It's difficult to comprehend how something so innocent could lead to such a devastating outcome. I want to clarify that she was not let out and forgotten outside; I received a call from my leasing office at 11:59 AM informing me she was on the patio and did not indicate there were signs of distress. Despite my frantic rush home, I couldn't save her in time."
"Zene was my emotional support animal and my cherished companion for the past four years, filling my life with joy and comfort. The rumors circulating about her passing are not only untrue but also deeply hurtful. During this painful time, I kindly ask for privacy as my family and I mourn our loss and honor Zene's memory. I am grateful to everyone who reached out to law enforcement, animal control, and the leasing office for their support."
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ABC7 spoke with local animal rights groups about what are a bystander's rights to rescue an animal in distress.
Cassie King is a volunteer for the Berkeley Animal Rights Center and Communications Lead for Direct Action Everywhere.
"As we see in this case the guardian is saying this was a tragedy that was unexpected and would've been grateful for someone to intervene if they could," King said.
In this case, Zene was on a fourth-floor balcony and someone would've needed to trespass.
"So California's Right to Rescue bill is specific to animals you see overheating in a vehicle and it's tragic that situations like this keep happening and our laws are not catching up," King said.
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King says we have a common law doctrine in the U.S. and other common law countries called the Doctrine of Legal Necessity.
"Legal Necessity says you can break a minor law to prevent greater harm like saving someone's life, human or otherwise, but the necessity defense hasn't been applied to non-human animals yet," King said.
Fleur Dawes is the Communications Director for In Defense of Animals based in San Rafael.
"If that had been a toddler, who had been on that balcony, you would be praised as a hero for going in and rescuing them. It should absolutely be the case that we enshrine in law protections for those who bravely step up and rescue animals too," Dawes said.
In a statement Thursday, police concluded the dog let itself out onto the balcony.
Investigators say there were no previous calls about animal welfare to that apartment.