A portion of a bridge in the Greater Sudbury area collapsed Sunday afternoon, sending several cars from a cargo train into water below.

Containers from a Canada Pacific train plunged into the Wahnapitae River after the train derailed Sunday near the community of Wanup, Ont., just south of Sudbury.

No injuries were reported, but the collapse and derailment caused major damage. Train containers and other debris could be seen floating downstream hours after the incident.

Greater Sudbury officials said in an earlier statement that the train contained some potentially hazardous materials, prompting the Sudbury and District Health Unit to issue a drinking-water advisory to residents who draw their water from the Wahnapitae River.

But CP spokesperson Ed Greenberg said in an email to The Canadian Press that initial inspections of the containers indicate there is no product that poses a threat.

Crews continue to work with officials to examine the condition of the containers and determine which ones made contact with the water.

For the time being, residents are being urged to visit four municipal filling stations in the city.

Greenberg said that initial investigations also indicate a wheel-bearing failure may have caused the freight train to derail just before it reached the bridge.

“Our early investigation indicates this incident is the result of an unexpected and catastrophic wheel-bearing failure that could not have been detected in advance,” Greenberg said.

The health unit and the Nickel District Conservation Authority are monitoring the situation. The Ministry of the Environment and The Transportation Safety Board has also been called to the scene.

Meanwhile, trucks carrying cranes and other equipment have been brought in to help with recovery and bridge repair.