WASHINGTON — Drivers along northbound Va. 123/Ox Road saw something unusual Wednesday morning — large prefabricated, concrete slabs in one of the lanes at Silverbrook Road in Fairfax Station, Va.

Two left lanes had to be closed as the slabs were removed.

All lanes are now open.

The concrete barriers, weighing thousands of pounds, came off the truck just before 5 a.m. Wednesday.

Police are investigating what happened.

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