Updated at 1:41 p.m.

Southbound lanes of Route 1 are closed from Slater’s Lane to First Street in Alexandria due to fallen electrical poles in the road, according to Alexandria police.

All lanes in both directions initially were closed, but northbound lanes have since reopened. Police estimate southbound lanes could remain closed into the evening.

It wasn’t immediately known what caused the poles to fall, but police said no traffic collision was involved.