A Sydney charity for families of children with special needs is mourning the loss of a boy who was hit by a train.
An 11-year-old severely autistic boy fatally struck by a train in Sydney's south after running away from his carer has been described as a "beautiful angel".
Police mounted a large search involving the dog unit and Polair after he ran off at Oatley shops about 7.15pm on Sunday.
The boy had been staying at Civic Disability Services Limited, a short-term accommodation facility for children and young people.
He was found dead at Oatley railway station about two hours after disappearing.
"This is a tragic and distressing incident and our deepest sympathies and thoughts go out to the child's family," Civic CEO Annie Doyle told ABC News.
"Counselling and assistance services have been made available to our staff and others who have been affected."
Sydney Friendship Circle, a charity for families of children with special needs, on Sunday night desperately pleaded with the public on Facebook to find the boy.
Hours later the group shared the heartbreaking news about his death. They described him as a "treasured son, grandson, brother and friend".
"Today the world lost a beautiful angel. As we try to process this tremendous loss, your beautiful life flashes in front of us," the group posted on social media on Monday.
"We are going to miss your mischievous smile, the joy in your eyes, your curiosity about the smallest creation and your zest for life."
State Member for Oatley Mark Coure said the incident was "just heartbreaking".
"My heart goes out to the family, friends and carer this morning of an 11 year old boy who last night was found dead at Oatley Train Station," Mr Coure wrote on Facebook on Monday.
"As a father, I can only imagine the grief of the family and extend my deepest sympathies for their unimaginable loss."