Work crews will shut down the Hawthorne bridge on Sunday for maintenance.
The closure will start at 7 a.m. and could last as late as 3 p.m.
Crews will perform annual maintenance that includes greasing counterweight cables and completing a repair on a drawbridge tower catwalk.
TriMet routes 4, 6, 15 and 33, which usually cross that bridge, will instead detour across the Morrison bridge.
In the event of heavy rain, the work will be rescheduled.
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