Simon was close with Nightbirde after she competed on , even awarding her his golden buzzer that put her straight through to the semi-final. On Tuesday, the 62-year-old paid tribute to both acts on his Instagram feed in separate posts. In his post for Jamal, he shared a photo of the late star and wrote: "I had the pleasure of meeting Jamal. He was an extraordinarily talented young man, so ambitious, a real entrepreneur and had a natural gift for talent.
"I was so very sorry to hear about his passing.
And paying tribute to Nightbirde, he penned: "Heart breaking news to hear about Nightbirde, she was an extraordinary person, so brave, so talented.
"She made a huge impact on AGT and the world, her courage was incredible and her determination to fight this terrible illness was remarkable. Rest in peace, Jane. I am sending my love to her family. Simon."
His 1.7 million followers were quick to offer their condolences as well, with many sharing heartbroken and crying face emojis.
"May his soul rest in eternal peace," one said about Jamal, while another added: "It's just shocking and so sad. I'm just glad he made his mark with music. That will live on forever! RIP Jamal."
One follower said Simon had a big impact on Nightbirde, as they said: "So true... but at least the golden buzzer made her life," and a second commented: "Rest in peace, sorry to hear that."
Nightbirde – real name Jane Marczewski – passed away on Sunday, following her brave battle with cancer.
Jamal passed away on the same day after a "sudden illness", and his mum, star , shared a heartbreaking message with .
The heartbreaking statement read: "It is with the deepest heartache that I confirm that my beautiful son Jamal Edwards passed away yesterday morning after a sudden illness.
"Myself, his sister Tanish and the rest of his family and friends are completely devastated. He was the centre of our world."