Harry's family friends, fans, even his bandmates have shared their condolences with the star.
And an eagle eyed has just noticed another tear-jerking detail.
A photo has started circulating the internet that shows Robin at Harry's London show last month dressed head-to-toe in Harry-inspired attire.
From the hat to the ripped jeans to the shiny boots, Robin paid the perfect homage to his step-son during the last time he saw him perform live.
Our thoughts and prayers are with Harry and his family at this tragic time.
Rest in peace Robin Twist <3.