OSLO (AP) — Investigators say a lack of safety precautions was the cause of a train crash at an Oslo industrial port that killed three dock workers.

In the March 24 incident, 16 train cars rolled out of a cargo terminal in the Norwegian capital and careened downhill for three miles (five kilometers) before derailing and slamming into a port building.

In a report published Monday, the Norwegian Accident Investigation Board blamed cargo terminal workers and railway officials for the accident, citing their failure to anticipate and prepare for the possibility of a runaway train.

The report says terminal workers failed to secure the cars' track brakes while railway officials failed to put in place acceptable strategies for stopping runaway cargo trains.