(WUSA) -- The westbound span of the Bay Bridge has reopened after inspectors determined that the bridge was safe.
Inspectors were examining the westbound span early Tuesday morning after workers on the bridge saw what officials call "unusual and slight vertical movement of the bridge" shortly after midnight.
On the eastbound span of the bridge, one lane remained open for westbound traffic and one lane stayed open for eastbound traffic. Traffic cameras captured a massive back-up (see photos and video attached).
Later Tuesday, MDTA officials said the vertical movement on the bridge that workers saw while painting it was caused by a strong wind. Inspectors determined the bridge was meant to function that way under those conditions and that the bridge was no danger.