(AP) CAMPO, Calif. - Authorities say a wildfire burning in rural San Diego County was sparked by two illegal immigrants who set a signal fire after they got lost.

California Department of Forestry and Fire Protection Battalion Chief Nick Schuler says the migrants made a cell phone call to Mexico’s emergency dispatch system Thursday afternoon saying they’d been lost for two days, were dehydrated and were going to set a signal fire so rescuers could spot them.

Schuler says remnants of a campfire were found, but there was no sign of the migrants.

The fire, between Campo and Potrero, has grown to 822 acres and is 42 percent contained. Full containment is expected Sunday.

No structures are threatened, no roads are closed and there have been no injuries.