The Dumbarton Bridge is closed because of a possible suicide attempt, according to the California Highway Patrol.
Police activity was reported on the bridge for traffic heading east just after 3 p.m. Tuesday.
Officer Brian Watkins said the closure of traffic in both directions is because of a person threatening to commit suicide on the span. Traffic is being held at University Avenue in Palo Alto and the Toll Plaza on the Hayward side.
Additional information was not available.