Three people died following a single vehicle crash in Kallista on 8 March.
Police believe the vehicle may have been struck by a falling tree and went off the edge of Sherbrooke Road just after 2.30pm.
There were five occupants in the vehicle, two adult males and one adult female died at the scene.
A child was airlifted to hospital with non-life threatening injuries and a female adult was taken to hospital by road with non-life threatening injuries.
Sherbrooke Road was closed to traffic in both directions between Owen Street and Braeside Avenue for some time.
Anyone with information or dash cam footage is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report at www.crimestoppersvic.com.au.