Riley Andersen Fowlow, 19, managed to get out of a privately contracted ambulance that was moving him from a hospital in Clarenville to St. John's.
About two hours after he fled into the woods near the Foxtrap Access Road, he was struck and killed early Monday morning by a transport truck.
Eastern Health is investigating the incident, including whether appropriate protocols were followed in the transfer of Fowlow by ambulance.
At the authority's annual meeting on Tuesday evening, CEO Vickie Kaminski took time to speak about Fowlow's death.
"We are saying that we are very sorry," she said.
"It's a terrible, terrible accident and absolutely we apologize to everybody involved for what's happened and we're sorry and we offer our sincere condolences."
Later, though, Kaminski told reporters that she had not spoken directly to Fowlow's family in Port Rexton.
Sources tell CBC News that Fowlow had a mental illness, and that he had become so agitated on Sunday night that police were brought in.
RCMP were called in after paramedics and Fowlow's father were unable to handle him. Police handcuffed Fowlow, CBC News was told, and took him to the hospital in Clarenville.
Sources said RCMP told Fowlow's family that the teen had again become agitated while he was being transferred to St. John's.
It's not known how Fowlow got out of the ambulance, nor what personnel were in the ambulance at the time.
Kaminski said a quality review of the incident is underway, and that it will take about two weeks to complete.
Kaminski, though, said she will not in the meantime describe details of what happened.
"We are investigating and are not going to make any comment until we finish our investigation," she said.