(KGTV) -- A brush fire that began in Mexico jumped to the U.S. side Thursday morning, prompting a response from San Diego County fire crews.
The blaze in Mexico was first reported at around 10:30 p.m. Wednesday, Cal Fire San Diego officials said.
Cal Fire said the fire initially burned five acres on the Mexico side, but crews continued to monitor the fire’s developments.
Early Thursday morning, the fire crossed into the U.S., charring about 50 acres in the Copper Canyon area of Otay Mountain.
At around 6:20 a.m., Cal Fire officials said crews on the U.S. side began making progress in putting out the flames. By 8 a.m., Cal Fire said crews stopped the fire's forward rate of spread on the U.S. side.
As of 7:30 a.m. Friday, Cal Fire said the so-called Copper Fire was 100 percent contained.
"Smoke from the portion of the fire in Mexico will be visible," Cal Fire officials tweeted.
There were no immediate reports of structural threats or injuries.
The cause of the fire is unknown.