The first person known for being diagnosed with autism has died at the age of 89.

According to multiple reports, Donald Triplett of Forest, Mississippi, reportedly died in his home on Thursday.

Don Triplett, a Mississippi native known as the first person diagnosed with autism, has passed away at the age of 89. https://t.co/LXBC7k72f7

— SuperTalk News (@SuperTalkNews) June 15, 2023

His background

"Triplett was born in Forest on September 8, 1933. At the age of four years old, his parents committed him to a state institution after noticing developmental delays but withdrew him a year later. In 1938, Triplett was examined by child psychiatrist Dr. Leo Kanner at Johns Hopkins Hospital in Baltimore, prompting Kanner’s quest to diagnose Triplett’s symptoms," Supertalk reported.

"By 1943, Kanner had seen 10 children with similar symptoms to Triplett. In his article 'Autistic Disturbances of Affective Contact,' Kanner referred to Triplett as 'Case 1' when outlining the disorder that later became known as autism," it added.

My thoughts and prayers go out to the family and friends of one of the City of Forest greatest friends and citizens Mr Don Triplett.

Mr Don was known world wide for being the first person diagnosed with autism, but to his friends in Forest he was just Mr Don. pic.twitter.com/0lknOyjOLt

— Rep Tom Miles (@reptommiles) June 15, 2023

His impact

"My thoughts and prayers go out to the family and friends of one of the City of Forest greatest friends and citizens Mr Don Triplett," State Rep. Tom Miles tweeted.

"Mr Don was known worldwide for being the first person diagnosed with autism, but to his friends in Forest he was just Mr Don. If he liked you and you were lucky enough he would give you a nickname, mine was TM when saw me," he added.

Don Triplett, autism case 1 and longest living known person with autism, dies https://t.co/1CncGq6hos

— The Advocate (@theadvocatebr) June 16, 2023

"But we saw something else when we went to Forest — and this is where we think the movie of Donald's life would get interesting. The town itself played a part in Donald's excellent outcome — the roughly 3,000 people of Forest, Mississippi, (sic Forest's population is closer to 5,000) who made a probably unconscious but clear decision in how they were going to treat this strange boy, then man, who lived among them. They decided, in short, to accept him — to count him as 'one of their own' and to protect him," the Advocate wrote, citing a BBC report on Triplett.

"We know this because when we first visited Forest and began asking questions about Donald, at least three people warned us they would track us down and get even if we did anything to hurt Donald. That certainly told us something about how they saw him," it added.

Triplett's impact extended far beyond his hometown. Though he was a local, he traveled the world as part of his adventures.

His example has impacted the lives of many, giving hope to others seeking to live life to the fullest with autism.

In his hometown, Triplett will be known for his deep love and care for others where he will forever be remembered.