A teenage boy who went missing from the National Autistic Unit of Bethlem Royal Hospital in Beckenham was found this weekend.
His dad, Richard Lincoln, told News Shopper Andrew was found "safe and sound" and he thanked everyone who picked up and shared the story.
In a Facebook post he added: "Thank you everyone who shared/reshared or phoned in possible sightings, sent messages of support or just shared positive vibes it made a huge difference."
Andrew went missing from the hospital on August 17 between 1.30am and 5.30am.
His parents turned to social media and local news outlets to help find their son and on Saturday (August 24) they reported the good news about Andrew being found.
It is understood that an investigation has been launched to find out how Andrew was allowed to wander off.
The South London and Maudsley NHS Foundation Trust has apologised to the family.