KINGSBURG (AP) — The California Highway Patrol was mourning the loss of two officers Monday after their squad car flipped over while responding to a multi-vehicle crash.

Officers Brian Law, 34, of Clovis, and Juan Gonzalez, 33, of Fresno, were heading to the crash on state Route 99 near the Central Valley town of Kingsburg when they swerved to avoid a person in the road and lost control of the vehicle, the CHP said.

California Gov. Jerry Brown and first lady Anne Gust Brown sent their regards Monday to the fallen officers and their loved ones. Flags will be flown at half-staff at the State Capitol in Sacramento.

“Anne and I extend our deepest condolences and sympathies to the families, friends and colleagues of Officers Law and Gonzalez as they mourn the tragic loss of these dedicated public servants,” Brown said in a written statement. “We join all Californians in honoring these officers for their courage, commitment and service.”

Law and Gonzalez were traveling southbound to get to the crash, CHP Capt. Dave Paris said.

The original pre-dawn collision about 25 miles southeast of Fresno was initially reported on the northbound side of the divided highway, Paris said. The officers soon realized, however, that the crash scene was actually in the southbound lanes, and one the drivers involved was on the road, Paris said.

Gonzalez, who was driving, swerved out of the way, and the squad car hit a guardrail and struck the pylon of a freeway exit sign, said Officer Axel Reyes, a CHP spokesman.

The original crash apparently occurred when a pickup truck driver fell asleep at the wheel and crashed into the center divider, the CHP said. It came to rest in the wrong direction with its lights off, setting off a chain-reaction collision.

“Prior to our arrival, it appears another vehicle may have hit the truck” and came to rest a short distance away, CHP Commissioner Joe Farrow told reporters in a briefing at the crash site.

“We’re not sure if the officers ... thought the crash was further down the road,” Farrow said. “(But) as they approached the scene, they lost control of their vehicle. They hit the guardrail and ultimately hit the sign.”

It is standard procedure for the two officers to be in the same car because they were working the graveyard shift, said Reyes, the CHP spokesman. Both Law and Gonzalez were wearing their seat belts, said Paris, the CHP captain.

The two officers graduated from the CHP academy in 2008. They are the first officers from the Fresno CHP office to die in the line of duty since Jerry E. Turre was struck and killed by a hit-and-run driver while laying flares at an accident scene in 1962, according to CHP records.

Farrow said Law and Gonzalez were good friends and partners who trained together. Now, their colleagues from across the state have to deal with their loss.

“It’s draining — a lot of the officers are drained,” Reyes said. “Officers are having a tough time — some more than others.”

Law started his career in Oakland before transferring to Fresno about a year ago to be closer to his wife and three kids, said Officer Sean Wilkenfeld, a CHP spokesman who worked with Law in Oakland.

“He was just a really fun, easygoing guy,” Wilkenfeld said. “He was sort of quiet, big into sports, and always willing to help out.”

Before transferring to the Fresno area in 2010, Gonzalez worked for CHP in San Jose for two years. He is survived by his mother, a sister and a girlfriend.

CHP Officer Ross Lee, who worked the graveyard shift with Gonzalez in San Jose, said Gonzalez, who had served as a field training officer, was a good mentor.

“He was a great guy with a very calm demeanor, a good officer who took the time to make sure he and others did their jobs correctly,” Lee said. “A stand up guy.”

Wilkenfeld said both officers will be missed by the entire CHP.

“I can’t count how many lives they made better,” Wilkenfeld said. “This is a huge loss for us and the communities they served. We know what we do can be dangerous.”

The CHP’s accident reconstruction teams remained at the site Monday afternoon to scour for evidence. One southbound lane was open and traffic was moving slowly, the CHP said.