Blake Ross, 13, was discovered unwell on a Lothian bus on Monday afternoon, two days after police launched a major search operation after he disappeared from Howdenhall.
The Police Investigations and Review Commissioner (PIRC) are now investigating officers’ actions in relation to the incident.
The teenager, who lived at St Katharine’s care unit, is understood to have suffered from diabetes and did not have access to his medication while he was missing.
Police Scotland confirmed Blake had been taken to the Sick Kids Hospital on Monday, where he died at around 9pm.
His death is currently being treated as unexplained and inquiries are continuing.
A passenger who was travelling on the number 4 Lothian bus around 2pm on Monday told how Blake got on the bus with his hood up and said he “slid down the bus stop” on Leopold Place after getting off the service.
She said: “I didn’t notice him getting on at first but after the ticket inspector appeared there was a small commotion happening at the front of the bus.
“I heard the boy, who was sitting with his hood up at first, tell the ticket inspector a few things including that he needed a hot drink. I think the ticket inspector knew it was Blake – the boy that was missing – as he kept communicating with the driver.
“The inspector asked him if he was feeling OK because he kept falling asleep.
“He really didn’t look well. Then when he got off the bus he stumbled and slid down the bus shelter. My thoughts are with his family.”
A parent who took a shine to Blake after the teenager bonded with his youngest daughter through their shared suffering from diabetes paid tribute to the youngster.
He said: “I knew him through the school because he was in the same class as my youngest daughter.
“I had a great bit of affinity for him because he’d look out for her at karate classes and I think they bonded as they both had diabetes. I felt for him as he’d gone through a lot at such a young age.”
He added: “He was quite a chatty, cheeky wee lad and although some people think he might have been a rascal they have to understand that he was going through a lot. Although I hadn’t seen him in a while, I recognised him immediately when I heard he went missing and hoped he’d be safe.”
Blake was reported missing from Howdenhall at around 3.15pm on Saturday.
It’s believed that he was intending to travel to Gracemount when he was last seen. Police said he also had links to the Moredun and Wester Hailes areas.
Last year, Blake was chosen by Edinburgh Leisure as the star of their fireworks display at Meadowbank Stadium, and was given the opportunity to press the button to begin the display after he appeared in one of their films. However, sadly the display was cancelled due to bad weather.
Tommy George, community development manager at Edinburgh Leisure, said: “Blake recently featured in a film about Edinburgh Leisure’s Looked After and Active programme showing how physical activity and sports impacts positively on the lives of young people in care.
“Everyone who came into contact with Blake is deeply saddened to hear this sad news and we send our condolences.”
Superintendent Lesley Clark, of Edinburgh Division, said: “This is a tragic death of a young boy and our thoughts are with Blake’s family at this very difficult time.
“In the coming days and weeks we will be working with our relevant partners to support his loved ones and provide them with all the necessary support and assistance they require.
“In addition, we will be continuing to conduct our investigation to establish the full circumstances surrounding Blake’s death and submit our findings to the Procurator Fiscal.
“Our inquiries are ongoing and we would ask anyone with information regarding Blake’s movements between the afternoon of Saturday and Monday to contact us.”
A spokeswoman for the Care Inspectorate said: “We have been properly notified of this tragic event and our thoughts are with all those affected.
“We are working closely with the care service and Edinburgh Council at this time.
“Whenever any young person in care dies, we look carefully at all the circumstances.”
A spokesman for the PIRC said: “The Crown Office and Procurator Fiscal Service (COPFS) has directed PIRC to carry out an independent investigation into police actions relating to the death of Blake Ross, 13, on Monday, February 13. A report on the Commissioner’s findings will be submitted to the COPFS in due course.”
A council spokesman said: The Care Inspectorate has been informed and there will be a multi-agency Significant Case Review in accordance with our procedures.”