UPDATE Feb. 29 9:30 am
SDOT announced this morning that this work has been cancelled. No further clarification or rescheduling was made public.

press release:

The contractor working for the Seattle Department of Transportation on the Spokane Street Viaduct Widening project will be closing the intersection of First Avenue S at S Spokane Street this coming weekend in order to repave the southern half of the intersection.

The intersection will be closed to all traffic beginning Friday, March 2 at 8 p.m. and will reopen on Monday, March 5, at 5 a.m. The eastbound First Avenue off-ramp from the West Seattle Freeway will also be closed. Motorists wishing to exit to SODO can still use the Fourth Avenue off-ramp, which provides motorists the option of then driving either north or south on Fourth Avenue S.

Southbound traffic on First Avenue S will be detoured west at S Hanford Street. Northbound traffic on First Avenue S will be detoured east at S Dawson Street, and then north on Fourth Avenue S.

Additional project details can be found at www.seattle.gov/spokane.