RIO VISTA -- A grass fire on one of the islands in the Sacramento-San Joaquin Delta sent giant plumes of black smoke into the air above Antioch and other East County cities Sunday, authorities said.

The fire was on the remote part of Lower Sherman Island that's not accessible by vehicle.

A Solano County dispatcher said Sunday night the agency could not confirm a report by KCRA in Sacramento that at least 15 acres had burned, but the agency did confirm that the fire was going to be allowed to burn itself out. No homes are on that part of the island, which is in inaccessible to fire crews.

Thick smoke hovers over a neighborhood in Antioch, Calif., on Sunday, March 17, 2013. (Paul Burarino/Staff)
Thick smoke hovers over a neighborhood in Antioch, Calif., on Sunday, March 17, 2013. (Paul Burarino/Staff)

Nobody was reported injured in the blaze, which spewed ash through the air to places as far away as Brentwood, according to several witnesses who contacted this newspaper. The smoke was particularly thick in areas of Antioch, Oakley and Brentwood, according to witnesses.

Neither Sutter Delta Medical Center or Kaiser Permanente Medical Center reported anyone complaining of smoke inhalation, shortness of breath or other possible effects from the blaze, according to emergency room representatives at the Antioch medical facilities.

David DeBolt contributed to this story. Contact Rick Hurd in Antioch at 925-779-7166 and follow him at Twitter.com/3rdERH.