Katie Cassidy lost her biological father, legendary singer David Cassidy, on Tuesday, and she's remembering him in a bittersweet way. People reports Cassidy posted a short remembrance of her dad on social media, underscoring the warning embedded in his final words. She wrote, "My father's last words were 'So much wasted time'. This will be a daily reminder for me to share my gratitude with those I love as to never waste another minute....thank you." Cassidy also thanked fans for "the solace our family's received." David Cassidy, who had a distant relationship with Katie, died at 67 after suffering dementia and organ failure.