Update 10:12 p.m. Cal Fire reported at 9:45 p.m. that one civilian sustained serious burns in the Buck Fire in the Aguanga area, 50 miles southeast of Redlands and Loma Linda.
A rescue helicopter crew was preparing to transport the victim.
Posted 9:12 p.m. An explosive wildfire on the south side of the San Jacinto Mountains grew so fast Tuesday afternoon smoke from the blaze could be seen east of Redlands and Loma Linda by sundown.
The drift smoke turned pink over Yucaipa Ridge and the San Gorgonio High Country before 8 p.m., while 50 miles to the south more than 200 firefighters in Aguanga near the Riverside-San Diego county line were assigned to the blaze, according to Cal Fire.
The fire was reported just before 1 p.m. Aug. 14 in Aguanga, scorched an estimated 1,800 acres, prompted evacuations, and destroyed at least one home.
Just after 6 p.m., the fire was considered 5 percent contained, according to a Cal Fire incident commander.
At 8:25 p.m., Cal Fire reported two firefighters were transported with minor injuries to a hospital and four structures were destroyed.
Earlier Tuesday afternoon, the fire broke out in triple-digit temperatures after more than a week of the same heat wave conditions Redlands and Loma Linda residents have coped with since the beginning of August.
Firefighters with the were among those assigned to the blaze, and there was concern Tuesday evening the fire could reach forest lands north of Aguanga and Lake Riverside.
Aguanga is about 40 miles south of Beaumont, 20 miles southwest of Idyllwild, and 20 miles east of Temecula.