A 42-year-old homeless man was found lying fatally injured on Kalanianaole Highway in front of Cindy Conradt’s Waimanalo house Friday night.

“All I heard was a big thump,” she said. “I didn’t hear a car rev off. … It was loud. It wasn’t like running over something.”

Vehicular Homicide police Sgt. Nathan Hee said, “We don’t know what happened, but we are investigating the incident as if it were a hit-and-run.”

Conradt said she went to grab the phone to call 911, then ran outside and saw a body on the road.

She said police asked her whether it could have been somebody throwing a body out of a vehicle, but she discounted that possibility and said she did not hear a car door slam.

“It didn’t sound like somebody hit the brakes,” she said. “It was like, boom, and gone.”

Patrol officers were flagged down 8 p.m. Friday by a motorist who found a man lying in the Kailua-bound lane, police said.

Police said the man, who has no local address, was bleeding from a head wound and was later pronounced dead at the scene.

The Medical Examiner’s Office will perform an autopsy Monday morning, which is the earliest his identity could be released.

Conradt’s sister, Loretta Wells, who lives next door to her, said, “The noise was really loud, and it was hard to distinguish if it went over something or I guess it bumped (something).”

A roadside memorial of coral pink roses in a glass vase and a couple of bouquets of colorful spring flowers marked the site Saturday morning.

“So sad,” said Shirley Dodson, 46, a nearby resident who arrived home 11 p.m. Friday by bus, which had to be detoured. “I was literally weeping last night.”