California wildfires on the brink of burning 4 million acres

A firefighter runs past flames Thursday while battling the Glass Fire in a Calistoga, Calif., vineyard. (AP Photo/Noah Berger)

SAN FRANCISCO — Red flag warnings of extreme fire danger subsided, but warm and dry weather continued to challenge firefighters battling more than two dozen blazes across California on Saturday as the state approaches an astonishing milestone: 4 million acres burned by wildfires this year.