A man found critically injured on a west Santa Rosa street last week died early Wednesday at Santa Rosa Memorial Hospital.

Mike Nunes was 62 or 63, had lived in Santa Rosa for at least 30 years and worked at a Chevron gas station on Hopper Avenue, family members said.

"He was a great big guy, in great shape," said his son-in-law, Leland Schneider of Santa Rosa. "And I know everyone says this, but he was the nicest guy ever. Not an enemy in the world."

The events leading up to Nunes' death are cloudy.

On the night they occurred, he probably was engaged in a daily routine, walking from his rented room on Partridge Court in west Santa Rosa to a nearby Rotten Robbie gas station, perhaps to buy cigarettes, Schneider said.

He was found unconscious at 9 p.m. Friday on Peterson Lane, near the intersection with Guerneville Road. He was in front of a vacant house, Schneider said. Police said he had life-threatening head injuries.

No witnesses to what may have happened had been located as of Tuesday, and police said it was unclear whether an assault or an accident of some sort accounted for his injuries. His injuries had prevented detectives from interviewing him.

His daughter, Sabrina Nunes of Gilroy, said late Wednesday that, "They are saying it's a hit-and-run."

The case has been transferred to the Santa Rosa Police Department's traffic bureau, which did not return calls seeking comment Wednesday. Investigators said Tuesday they were seeking a compact white car with a loud exhaust system that was seen Friday night in the area with two men inside, though it was unknown if the car was connected to the incident.

Nunes' family members say they believe he may have been attacked, based on his injuries.

"The first day I went to see him, he was basically naked, and I didn't see any trauma probably from the neck down, almost for sure from the chest down," Schneider said.

He said Nunes had scratches on his knuckles, an abrasion on his elbow and, according to hospital staff, multiple fractures around his eyes. His principle visible injury was on the top of his head, Schneider said.

"We have a really hard time believing it was a hit-and-run, because his injuries were so severe and from the head up," said Jackie Hadley of Healdsburg, his stepdaughter.

She said that there are video cameras on the traffic signal at Guerneville Road and Peterson Lane, about 30 yards from where Nunes was found, but that they are not working.

That could not be confirmed Wednesday night.

Police have asked anyone with information to call 543-3639.

You can reach Staff Writer Jeremy Hay at 521-5212 or jeremy.hay@pressdemocrat.com or on Twitter @jeremyhay.