CHICAGO (CBS) — A massive search is underway Sunday for a teenager who went missing after jumping into the Des Plaines River in unincorporated Cook County, officials said.

Three teens jumped from a railroad bridge about 4:30 p.m. Saturday just southeast of First and North avenues near Melrose Park, according to Patrick Waldron, a spokesman for Canadian National Railway. Two of the teens surfaced, but the third went missing.

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The bridge runs through Thatcher Woods, across the street from Dominican University.

Canadian National Railway police are working with the Melrose Park Fire Department, which is coordinating with multiple agencies in the recovery attempt, Waldron said.

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Cook County Forest Preserves police, the first to respond to the call, were also helping in the search with Illinois State Police and the Chicago Fire Department, a forest preserves spokeswoman said.

Additional details, including the reason why the teens jumped into the river, were not available Sunday morning, Waldron said.

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