Harrison Wagner's Brother & Girlfriend Pay Tribute After His Death

Harrison -- the youngest child of "General Hospital" alums Jack Wagner and Kristina Wagner -- was discovered in a Los Angeles parking lot on Monday, per a Los Angeles County Medical Examiner-Coroner report, according to Us Weekly. He was pronounced dead around 5 a.m. in North Hollywood, California.

Following the news of Harrison's passing, his brother, Peter Wagner, and his on-again-off-again girlfriend, Sophia Bui, shared touching tributes on social media.

Peter, 31, posted a series of throwback images of himself and his younger brother, as well as solo photos of Harrison, including one of him in his high school football uniform.

"Always with you," Peter captioned the Instagram post.

Sophia -- who was in a relationship with Harrison "on and off" for several years -- spoke out about Harrison's passing in an emotional Instagram post, revealing that the couple had made plans to see one another on Friday.

Alongside a sweet photo of herself and Harrison, Sophia wrote, "Here's a love letter to babe. I'm so broken hearted."

"We had plans this Friday and you called to apologize," she continued. "Seven years, on and off, round and round we loved each other. For better or for worse. In sickness and in health."

"Sorry, I missed yr calls in the middle of the night these last few days," added, before listing the things she already misses about Harrison. "I miss sleeping in yr pola bear arms, curled up. I miss sending you silly animal videos. I miss you sending gorgeous songs that made me cry."

Sophia -- who is an actress -- concluded her post with a heartfelt message.

"I was never alone in this world with you. You were the balm that soothed my soul. You were my guy. I hope I was that comfort for you. I will always be yr baby, babe. I will always choose to love you in this world and in any other life. 💔💔💔💔💔💔 @harrisonwagner."

The cause and manner of Harrison's death are still unknown as the Los Angeles County Medical Examiner-Coroner filing noted that the case has been "deferred pending additional investigation."

On Wednesday, a spokesperson for the L.A. Coroner's Office shared a statement with PEOPLE, offering further details about it means for a cause of death to be "deferred."

"Deferred means that after an autopsy, a cause of death has not been determined and the medical examiner is requesting more investigation into the death, including additional studies," the spokesperson told the outlet. "Once the tests/studies come back, the doctor evaluates the case again and makes the cause of death determination."

Jack, 62, and Kristina, 59, haven't posted or commented on Harrison's death. The former couple tied the knot in 1993 and divorced in 2006. In addition to Harrison and Peter, Jack also has a 34-year-old daughter named Kerry from a previous relationship.

Harrison last posted on his Instagram profile on May 22. Captioning a photo of himself sitting on a bench, above, he wrote, "Focus. YOU are left with YOU and your thoughts. 🤔." Following the news of his death, fans have flooded the comments section, expressing their sympathies and sorrow.