Update 12:41 p.m.: Good news, the BART station is open again, but there are still some residual delays.
Update 10:43 a.m.: Train service has resumed on the Richmond line, but the El Cerrito Plaza remains closed and trains will not stop at that station.
Update 10:15 a.m.: BART confirmed that there is a person under the train. Trains are being turned around at North Berkeley and BART has called for bus service.
Update: There is no service between El Cerrito Plaza and Richmond station and between El Cerrito Plaza and North Berkeley. BART is asking commuters to seek alternate means of transportation.
We're getting word now that there is a "major medical emergency" over in the East Bay, forcing police to close down the El Cerrito Plaza BART station.
There are no details yet, but BART officials are warning of major delays at El Cerrito Plaza in the Fremont, Richmond and Millbrae directions.