Update : 7:42pm:
The fire district has divers in the water in that area now and they have found some luggage and aviation charts. The crash happened close to downtown Antioch. No traces of the plane or passengers had been discovered by 7:30 p.m. Sunday.
A small plane crashed into the Delta near Antioch shortly after 5:30 p.m. Sunday.
First responders say they have located the wreckage.
Contra Costa Fire Dept. is on scene and will provide additional details shortly.
Fire officials have not detailed how many people were on board or what kind of aircraft is involved.