The NBA player released a statement regarding The Bachelor star's passing, saying, "I'm deeply grateful for all the love and support we have received from family, friends and fans. Gia was the most beautiful person I knew inside and out and she always smiled and made everyone else around her smile."
He continued, "She had such an amazing impact on my life and anyone that knew her was blessed. All I have left is to cherish those memories we made together and help perpetuate the many values, faith and love that we shared."
The 29-year-old was taken off of life support earlier today and died after losing critical brain and organ function following an apparent suicide attempt, according to Allemand's rep.
She was found unconscious in her New Orleans home Monday night by Anderson, who called 911. An emergency medical crew rushed Allemand to University Hospital, where she was said to be in critical condition yesterday.
Sources tell E! News that Gia and Ryan were experiencing relationship trouble recently, however they didn't necessarily appear to be headed for a breakup.
Allemand "passed away peacefully with her mother, boyfriend, and other life-long friends by her side. As a practicing Christian, Gia did receive the sacrament of last rites," her rep said in a statement.
"Loved ones and fans will remember Gia Allemand as a caring woman who loved her family and was well-known for her compassion towards animals and mission to rescue homeless pets. Funeral arrangements will be forthcoming in another official statement once available. On behalf of the family, we sincerely ask for privacy at this time."
Allemand became a reality TV star after becoming the fan favorite on Jake Pavelka's season of The Bachelor and later on Bachelor Pad.
If you or someone you know needs help, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).