Firefighters Contain Lake Henshaw Blaze : Arson: Officials offer $5,000 reward for information leading to arrest of the culprit who set the fire.

Some 1,500 firefighters continued Sunday to battle the brush fire that has blackened 4,350 acres in North County since it began Thursday in the midst of a record June heat wave.

Officials said the blaze in a remote area near Lake Henshaw was deliberately set and they are offering a $5,000 reward for information leading to the arrest of the arsonist.

By late Sunday, the fire was contained and 40% controlled, spokeswoman Audrey Hagan of the California Department of Forestry said.

Although fire officials had been more optimistic about containing and extinguishing the blaze sooner, gusting winds, heavy brush and high temperatures in the area were forces to be reckoned with, Hagan said.

June’s record-breaking heat set in the same week that 11 brush and range fires flared up around the county, most of them deliberately set, according to fire officials.

The forecast calls for temperatures to remain slightly above normal, according to the National Weather Service, but temperatures are not expected to reach the sizzling levels that fueled the wildfires last week.

The forecast for Independence Day is fair after morning low clouds, with highs in the mid-70s downtown, low 70s at the beach, mid-70s along the coast, mid- to upper 80s inland, high 80s in the mountains, and a blistering 100 to 110 degrees in the desert.

Firefighters had contained the Lake Henshaw blaze by Sunday morning, meaning they established a line around the fire, Hagan said. However, spot fires within the area continued to flare up throughout the day, she said.

The intense blaze, the largest since the June 1 start of the county’s brush-fire season, began at 2:15 p.m. Thursday and forced the evacuation of a Boy Scout camp and 20 homes in the small San Felipe community, the forestry department reported.

The fire was set deliberately with a matchbook-type device, according to Chief Steve Robertson, forestry department fire investigator.

“We do have some leads, but we don’t know where they’ll take us,” he said.

The fire, also called the Morettis Fire after the small community near where it began, started about half a mile south of the junction of California 76 and 79.

Robertson said there doesn’t appear to be any connection between this fire and other brush fires that have burned a total of 6,000 acres countywide since a week ago.

He said fire officials in San Diego County are keeping in contact with other fire agencies in Southern California, including those in the Santa Barbara area. “At this point, there doesn’t appear to be any common denominator between the fires,” Robertson said.

At the peak of the Lake Henshaw fire Friday afternoon, 1,827 firefighters waged war against the flames with the aid of five air tankers, four helicopters, 89 engines, 76 hand crews and four bulldozers, Hagan said. Crews were scaled down to about 1,500 Sunday.

The only injuries reported were 10 firefighters who suffered minor injuries. Only six structures in the Mataguay Scout Reservation area were destroyed, Hagan said.

Temperatures at Lindbergh Field reached 78 degrees Sunday, slightly higher than the normal 74 degrees. Last Tuesday, the high at Lindbergh soared to 94 degrees, tying the 1976 record high for the day. Wednesday’s high of 91 broke the 1976 record high of 90 degrees, according to the National Weather Service.

June was also a record month for rainfall. The wettest June recorded 0.87 of an inch, all from one storm. The old record was 0.68 of an inch, in 1850.