After days of searching for his missing daughter, Hannah Kobayashi's father was found dead over the weekend in Los Angeles. Although a cause of death has yet to be confirmed, his family tells PEOPLE they believe he killed himself amid a mental health emergency.

“He died of a broken heart,” says Larie Pidgeon, 45, his former sister-in-law and Hannah's aunt.

Ryan Kobayashi, 58, was recently retired and had joined his extended family searching for his 30-year-old daughter, who vanished earlier this month after missing her connecting flight at Los Angeles International Airport (LAX) and sending "alarming" texts to loved ones.

“We’ve been searching tirelessly,” Pidgeon says. “I think it just became so overwhelming for him driving the streets, going to Skid Row and seeing where his daughter could possibly have ended up."

Pidgeon suspects that as time "went on and on and on," Ryan's mental health deteriorated.

“We really want everyone to know that he fought so hard,” she adds. “Imagine if it was your daughter.”

At 4 a.m. local time on Sunday, Nob. 24, the Los Angeles Police Department responded to a parking lot near LAX for a death investigation.

A spokesman previously told PEOPLE that law enforcement was called to the area for "an apparent suicide." A cause of death has not yet been determined by the L.A. County medical examiner, but online records show that an examination has been scheduled.

The family confirms the parking structure is near the hotel where the family has been staying.

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Pidgeon remembers her former brother-in-law as "one of the kindest, most sensitive souls I’ve ever had the privilege of knowing."

“He was just so good,” she says. “He was a teddy bear. Through this whole process he’s just been thanking everyone endlessly with gratitude and love."

The family wants to dispel any rumors that he had anything to do with his daughter’s disappearance and says they do not believe he was lured to his death, according to Pidgeon. Police have not publicly accused anyone of wrongdoing in Hannah's case.

“He wanted to do everything he could,” Pidgeon tells PEOPLE of Ryan. “He showed up when it mattered the most.”

Despite the loss, the grieving family continues searching for Hannah, who has been missing since Nov. 11.

“We are holding onto hope and turning to our community for help. Now, more than ever, we need you," read a message shared by loved ones on a Facebook page dedicated to finding Hannah. "The search for our beloved Hannah must continue with the same love and determination that Ryan would have wanted. We need your help, we need your strength.”

"She is still out there, and we believe that together, we can bring her home," the message continued.

Pidgeon tells PEOPLE that the family will also keep searching. “We’re still here,” she says. “We’re a family doing the best we can now with two tragedies. So please be kind."