Sam Wolson / Sam Wolson / Special to The Chronicle

BART lines are seeing delays Wednesday afternoon after a person was apparently hit by a train, forcing a closure of the Lake Merritt station as medical responders work on the scene, according to BART.

The transit agency alerted riders to the closure via social media about 5:36 p.m., stating there are delays in the Dublin/Pleasanton, Warm Springs, Richmond and Daly City directions due to the medical emergency, with no direct service to Warm Springs from Richmond during the emergency, BART stated earlier. AC Transit was made available to riders while the station remained closed.