Police Chief Louis Kealoha bowed his head before a memorial erected to patrol officer Garret Davis on Sunday, then implored Oahu drivers to be more careful — especially when officers are doing their jobs.

"This is the second time in less than six months that an HPD officer has been killed on our roadways," Kealoha said. "Our officers risk their lives daily to protect our community, and I am pleading with all of you to help protect them while driving with care when you see them performing their duties on our highways."

Kealoha stood near the makeshift memorial to Davis at HPD’s Beretania Street headquarters, which contained a framed photo of Davis in his Hono­lulu Police Department uniform, white dress gloves, riding boots and a police whistle and keys next to a burning candle.

Davis was killed Saturday in the far left lane of the eastbound side of the H-1 freeway at the Kaonohi Street overpass in Aiea after he stopped to help stranded motorists.

His death came after HPD Officer Eric Fontes was struck and killed on Sept. 13 along Farrington Highway near Ko Olina while helping fellow officer Herman "Sam" Scanlan during a traffic stop.

Fontes, 45, died when he was struck by a pickup truck. Scanlan was injured when the pickup then hit a Dodge Durango that crashed into him.

"People gotta slow down on the highways," Kealoha said Sunday.

Davis, 28, grew up in Folsom, Calif., attended San Francisco State University and moved to Hono­lulu to join the Police Department, HPD spokes­woman Caro­line Sluy­ter said.

Davis has a young daughter who lives in California, Sluy­ter said. Services are pending.

He graduated from the HPD academy in 2008 with the 161st cadet class and had been assigned to the Wahiawa substation as a patrol officer.

Davis was delivering paperwork Saturday night to the main headquarters on Beretania Street when he stopped on the H-1 freeway to help a 32-year-old man and a 22-year-old woman in a stalled vehicle, Kealoha said.

Davis had turned on the blue lights to his patrol car when he was struck from behind, allegedly by a 41-year-old man driving a Chevrolet Silverado, Kealoha said.

"Officer Davis turned on his blue lights and stopped behind the stalled vehicle to shield it from oncoming traffic and to alert other drivers to the stall," Kealoha said.

Davis’ patrol car was then rammed into the stalled vehicle and caught on fire, Kealoha said.

"He didn’t even have a chance to get out," Kealoha said.

Emergency Medical Services personnel said the officer’s car was hit at 8:19 p.m., sending it crashing into a pickup truck.

The couple Davis was trying to help was taken to a hospital in guarded condition, Kealoha said.

The driver of the Silverado was arrested on suspicion of negligent homicide when he was released from a hospital, Kealoha said.

The crash occurred in clear weather, but investigators are trying to determine whether speed or alcohol were factors, Kealoha said.

"Officer Davis was a fine young officer beginning his career in HPD," Kealoha said.

In 2010, Davis received HPD’s Certificate of Merit for helping save a suicidal woman two miles offshore in Hale­iwa while riding on a Hono­lulu lifeguard personal watercraft.

"Although not a swimmer himself, Officer Davis assisted lifeguards on a personal watercraft and was able to bring the woman ashore safely," Kealoha said.

Saturday night, Davis "was again trying to help others when the fatal collision occurred. … We are devastated by his loss, but we send our prayers and condolences to his family," Kealoha said.

Emergency workers are pushing lawmakers to pass a bill requiring motorists to give a one-lane safety cushion, or to slow down, when driving around an emergency vehicle stopped on the road.