NATCHEZ — When Tyler Thompson was 18, he was diagnosed with leukemia, and today his parents are going to his funeral.

Thompson, 21, died Sunday at M.D. Anderson Hospital in Houston.

And while his mother, Ramee Thompson, said he valiantly fought his disease, it wasn’t the leukemia that ultimately took his life.

At the time of his death, Tyler’s leukemia was actually in remission.

“In his mind he beat cancer,” Thompson said. “But he was still fighting.”

Thompson said extensive radiation treatments damaged her son’s lungs so badly that when he went on a ventilator to aid his breathing he was never able to breathe on his own again.

“He died very peacefully in his sleep,” she said. “And we can take comfort in that.”

And while Tyler had been battling leukemia for years, his mother said his family still wasn’t prepared for his death.

“We weren’t ready,” she said. “We thought he could beat this. But this is God’s will.”

So confident were Tyler and his family in his ability to beat cancer that in August Tyler got engaged to be married.

“She’s going to have a hard time,” Thompson said of Laura Usnik, Tyler’s fiancée.

Tyler met his bride-to-be when they were both in high school at Adams County Christian School.

The couple graduated in 2005.

While Thompson said her entire family is saddened by their lost, at least one part of Tyler will live on.

Tyler chronicled his experience on the Web site caringbridge.org.

The Web site is devoted to those fighting cancer and documents their struggles.

Tyler and his mother have more than 400 entries on the site.

In one of his last entries, in November, Tyler jokes about how he used his sickly appearance to sway an employee at a video game store to sell him the store’s copy of the out of stock game.

“But I guess the mask, bald head and walking cane did the trick and the dude sold me their display copy,” Tyler wrote.

“We are going to miss him,” his mother said.

Tyler’s funeral is at 1 p.m. today at Laird Funeral Home Union Street Chapel.

Tyler was a student at Jones County Community College and an avid participant in Relay for Life.