An over-width freight train Thursday morning sideswiped the Tukwila commuter-train stop overnight, breaking part of the wood platform where passengers board the northbound Sounder trains.

As a result, the northbound platform is closed, and all passengers must use the southbound platform, according to a Sound Transit news release.

Passengers should be prepared for minor service delays while repairs are being made, the release says.

Sounder and Amtrak trains travel on tracks owned by the BNSF Railway.

It's not known how much repairs will cost or when they will take place, Sound Transit spokesman Bruce Gray said.

The existing wood platforms, used for 700 train boardings per weekday, are to be replaced by a $16 million station in 2013.