06/06/2013 04:54 EDT | Updated 08/06/2013 05:12 EDT

Drugs, alcohol ruled out in teen party bus death

The B..C. Coroners Service has ruled out drugs and and alcohol in the death of a 16-year-old boy who collapsed while riding a so-called party bus in Surrey.

Ernest Azoadam, of Flores Island, near Tofino, could not be revived and died in hospital Feb. 15.

- Father demands answers about teen party bus death

Coroner Vincent Stancato said it's not clear what led to the teenager's death.

"There were certainly low levels of both alcohol and cannabis in his system, but neither would suffice to explain his death," he said.

Originally, alcohol and drugs were believed to have caused Azoadam's death, which spurred calls for stronger oversight for the party bus industry.

The coroner's investigation into the cause of the death is continuing.