Update, 3:38 p.m.
The wreck has been cleared and all lanes on the causeway have been re-opened.
A multiple-vehicle accident is causing major delays on the Galveston Causeway this afternoon.
The wreck happened around 3 p.m. on the outbound side of the bridge, near the Galveston side.
Police and first responders are at the scene and the wreck is being cleared.
The wreck has caused a traffic jam on the island as far as 71st Street in Galveston.
This is a developing story. Check back later for more details.