MEMPHIS, Tenn. -- Tuesday, St. Jude remembered Robin Williams for all the smiles and laughter he brought to patients.
The comedic actor was a huge supporter of the children's hospital. He loved to spend time with patients and raise awareness for the hospital.
Since 2009, 10-year-old Darcy Cassidy fought a highly aggressive form of brain cancer.
St. Jude asked her to be in a commercial with Williams last year after she found out the tumor came back.
"He was funny and nice," Darcy said.
"He was so compassionate. He was humble. He was honored to meet us, the parents of Darcy who were living this world and living with cancer," said Darcy's mother, Cathy Cassidy.
Darcy and her mother no idea the commercial would be his last.
Not only did Williams do many campaigns for St. Jude, he also visited one-on-one with patients. He made them smile and laugh at a time they needed it the most.
"I think Robin Williams was one of a kind. I don't know if he can be replaced. It is definitely a loss we are going to face," said Kelly Schulz, St. Jude vice president of marketing.
As for Darcy, her mother said she hasn't quite grasped her funny friend will no longer be checking in on her.
"He wondered about Darcy. He asked about Darcy, and he meant it," said Cassidy. "She met a very funny person who made her feel good for the hours we were with him, and she will take that in her heart forever."
In a news conference Tuesday, investigators said Williams died from hanging himself in his home. They said he also cut himself.
A publicist said Williams had long suffered from depression, and recently had been treated for it.
If you or someone you know is struggling with depression and needs immediate help, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255), or call (901) 274-7477 to reach the Memphis Crisis Center directly. Help is available 24 hours a day, seven days a week.