Police said a semi-truck crashed into the pole just before 9 a.m. near the intersection of Yale Avenue North and Stewart Street.
No one was hurt, but the crash knocked down a transformer and wires, cutting power to customers in the Capitol Hill, First Hill and South Lake Union neighborhoods.
Crews blocked off roads in the area, which caused traffic backups for drivers trying to get off and on nearby I-5. At its peak, the backup on the mainline stretched from Downtown to about Northgate Mall while the line to exit Stewart on the Express lanes was about 1/2 mile.
Seattle City Light said service should be restored by noon for customers who lost power.