Reservoir Avenue is closed to northbound traffic at Maefair Court due to repair work for a broken water main, police said.
"Traffic will be detoured until sometime in the early morning," Trumbull police said. "This may cause delays during the morning rush hour."
Some Trumbull residents can expect traffic delays or water outages as a result.
Crews responded to begin repair work at 6 p.m. Tuesday.
It was not clear when the repairs would be completed.
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