Relatives and friends said Nunn, 37, his wife Tanya, and neighbors Craig Wilson, 36, and his wife, Michele, were killed when Nunn's four-passenger Piper Cherokee crashed Saturday evening.
The Clark County, Nev. Coroner's Office said this morning that its confirmation of the identities of the plane crash victims is still pending.
A news release issued by BART, where Wilson served as a police officer, said his colleagues were honoring him by wearing black bands over their badges.
The Web site for the city of Oakley posted a release extending sympathies to the Nunn and Wilson families in addition to furnishing information for the trusts, which will help support the Nunns' four children - ages four to nine - and the Wilsons' three children, ages three to 14. Oakley City Councilman Kevin Romick set up the trust.
Donations can be made to Bank of the West in Oakley, in the name of the Nunn Children Trust and Wilson Children Trust. Anyone who wishes to donate only needs to mention the name of the trust. The bank can be contacted at 925-625-2211.
Nunn, a licensed pilot, did not arrive as expected at Byron Airport in Byron at 6:30 p.m. Saturday in his four-passenger Piper Cherokee.
The plane went down around 2:45 p.m., killing all four passengers and sparking a fire.
"The plane appears to have struck power lines about 20 miles northwest of the North Las Vegas Airport," Gregor said.
Residents in the crash area were evacuated from the resulting fire, but no injuries were reported on the ground, according to U.S. Forest Service spokeswoman Lisa Ross. The fire was 85 percent contained Sunday evening, she said.
Jim Laurie, a 15-year resident of the Mount Charleston area, said he was in his yard when the plane crashed.
"I looked up and saw a plane maybe 1,000 feet above my house," he said. "It's quite unusual to see a plane that low. It sort of looked like he was looking for a place to go down."
About 10 seconds later, the power went out in Laurie's house and he saw a plume of smoke about a mile away.
When Laurie arrived at the crash site, he said, it appeared the plane had been headed for a clear spot near a trailhead and parking lot on the wooded flank of 11,916-foot Mount Charleston, the eighth-tallest peak in Nevada.
The crash occurred about 100 feet away from eight upscale homes, Laurie said.
"It could have been a lot worse."
He said the plane looked like it had melted instantly, and he saw badly charred bodies.
Nunn family friend James Frazier, who serves on the Oakley Planning Commission, which is chaired by Nunn, was with the family through the night. Nunn, 37, and his wife Tanya have four children - three daughters and a son.
Frazier tearfully confirmed that the Nunns and Wilsons, who have three children, were due to arrive from Las Vegas at Byron Airport on Saturday after celebrating an anniversary.
According to an online FAA database, Nunn received his pilot's license in September 2006. On Nunn's campaign Web site, he said his real joy was flying and he frequently gave friends aerial tours of East County.
Nunn, chief financial officer for a construction firm, used the plane primarily for business, said David Huerta, a fellow planning commissioner and campaign aide. Huerta said Sunday evening he was still in shock over Nunn's possible death.
"He was a jovial, very caring person," he said. "He cared deeply about Oakley and he cared deeply about his family."
A fund for the two couples' children will be established at the Bank of the West in Oakley today, Frazier said. The BART Police Officers Association also was setting up a trust fund for the Wilsons' children.
Nunn finished second in June's District 5 supervisor's race and was set to face incumbent Federal Glover in a November run-off election.
Nunn's possible death might push third-place vote-getter Gary Agopian into the run-off election, Contra Costa County Clerk-Recorder Stephen Weir said Sunday after a preliminary look at election laws. County counsel planned to discuss the matter today, he said.
"There's time and no urgency on this issue," Weir said. "We are shocked and saddened by any tragedy that affects any family or individuals, but also understand we have a role in this."
Agopian was on vacation this week and could not be reached for comment. Glover called the accident "sad and devastating" and said it was too early to worry about the political consequences.
"It has not been the time for me to think about that," he said. "My thoughts go out to his family, and his children in particular."
Wilson had been a BART officer for nearly five years, said Linton Johnson, a spokesman for the transit agency.
"It's a tremendous loss to the department," he said.
Oakley city leaders planned to meet today to discuss how to help Nunn's family. City Manager Bryan Montgomery called Nunn "one of our own."
"They're just a nice family with nice young children," he said. "It's a real tragedy."
Flying in the desert during the summer can be difficult for single-engine planes, said Steven Elefant, a Lafayette pilot who is familiar with the North Las Vegas Airport. Warm weather hinders planes from climbing, he said.
Weather in the Las Vegas area was well into triple digits at the time of the crash.
"It's something you have to watch for," Elefant said.
Staff writers Paula King and Robert Salonga contributed to this story.