A train derailed when a bridge in Canada collapsed, threatening to send five carriages carrying a diesel-like substance into a river, officials said.
Efforts were under way to stop the cars falling off the slowly sagging bridge near Calgary and then pump out the yet-unspecified but potentially flammable liquid. No injuries were reported.
"It appears that the bridge is failing," said emergency management director Bruce Burrell. The train derailed after a section of the bridge dropped 2ft.
Each car could have 36,000kg of flammable product, said acting fire chief Ken Uzeloc. He could not specify what the liquid is. A sixth car on the bridge is an empty oil tanker, he added.
Canadian Pacific spokesman Ed Greenberg said the bridge gave way after most of the eastbound train had crossed. He said: "The (derailed cars) are all upright. There are no leaks reported and no injuries reported as a result of the incident."
The bridge, south-east of Calgary, is typically about 25ft above the water level, though the levels is currently high after flooding last week. Emergency crews were working to string a cable through the rail cars to secure them to bulldozers on land to prevent them being carried down the river in case the bridge gives way.
Mr Uzeloc said crews then hope to pull another train along a parallel bridge so the cargo can be pumped off and the empty cars can be removed with a crane. He said: "The last thing we want is these cars floating down the river and causing problems downstream." Booms were being deployed down river in case of any spills.
Canadian Pacific said the bridge was inspected by a qualified inspector last Saturday and the track was inspected on Monday.
Calgary Mayor Naheed Nenshi questioned the timing of the last bridge inspection when water on the river was still at record levels. He said he knows a lot of railway employees have been laid off, and he was angry that it took him six hours to contact Canadian Pacific officials.
"How many bridge inspectors did they fire?" the mayor asked. Officials said it was too early to say whether the structural failure was specifically due to flooding.