Technical tests have been completed on the coach that crashed in the canton of Valais last month, killing 28 people, 22 of them children.

Authorities say a final conclusion is expected in a couple of weeks.

For the past month, experts have been investigating the breaks, the accelerating system, the steering and other technical aspects of the bus to see if one of these could be to blame.

Investigators say they’ve also now received the autopsy reports from Belgium.

These could help determine whether human error or the driver’s health could have caused the crash.