A 5-acre fire burning near Copperopolis was caused by a man accidentally falling a tree into power lines, according to Cal Fire.
The blaze on the 3000 block of Paint Road was 40 percent contained Thursday afternoon.
As of 2:45 p.m., Paint Road was closed to non-residents due to the downed power lines.
No structures were threatened, Cal Fire said.
A total of 64 personnel were assigned to the fire. Equipment included eight bulldozers, eight fire engines, two hand crews, one air attack plane, one tanker and one helicopter.
Cooperating agencies included the Copperopolis Fire Protection District and the Calaveras County Sheriff's Office.
Cal Fire said an adult man lost control of a tree falling operation and a tree fell into some power lines, starting the fire. The man's named was not released.
Pacific Gas and Electric Co. was notified of the downed lines.