Their clothes were soaked and the end-of-day sun was slipping behind the San Gabriel Mountains.
Stranded, the group of 15 hikers sent out electronic Hail Marys from a cellphone in the form of a "Help" text message to a relative and a 911 call to a local sheriff's station.
But help wouldn't find them Sunday night.
The fog was too thick for helicopters or light aircraft to navigate the rugged terrain and their location was too remote to be seen from a trail in the darkness.
So the Huntington Park church group — 11 adults and four juveniles participating in an annual trek in the mountains — made a campfire on the flank of a steep hillside above Pasadena and prepared to spend the night deep in Eaton Canyon.
"We were wet, we were tired," hiker Nancy Picado said. "But we just decided the best thing we could do was to stay there and rest."
The group's day began like that of so many others who converge on Southern California's hiking trails on weekends looking for a respite from urban life. But a wrong turn, a miscalculation in time or distance can bring trouble.
Rescues of lost hikers are common on hillside trails from Malibu to Big Bear. But Eaton Canyon, with its picturesque waterfalls and steep, narrow canyons, has a particular problem.
Picardo and other members of the church group said they lost track of the time as the afternoon wore on and the darkness seemed to come quickly. To keep warm, they huddled together around the campfire.
By Monday morning, after the fog had burned off, helicopters could begin circling the rugged backcountry. The group was spotted on the hillside where they spent the night and airlifted — four at a time — to nearby Henninger Flats, a dusty perch from where hikers typically bend to the left to reach the first of two waterfalls.
Two of the hikers sustained leg injuries during the rescue and two others suffered hypothermia from the overnight exposure, authorities said. Overnight temperatures in the Mt. Wilson area dropped into the low 40s.
But considering the risks and potential for serious injury in an area known for its treacherous terrain, authorities said they were impressed by the group's chipper spirits and good health.
In the long history of Eaton Canyon rescues, Monday's incident was unusual for its size, officials said.
"Around here there's so many people up there hiking, this doesn't happen much," said Deputy Johnie Jones of the Los Angeles County Sheriff's Department. "What we usually find here is people that end up in places they shouldn't be."
Claudia Ortiz, one of the hikers who suffered a leg injury, said it was the group's decision to huddle together and share their body heat that helped them survive the night.
"Nothing happened to us, thank God," Picado told reporters minutes after she was rescued.
Jones credited the group's calm and ultimate decision to stay in one place with aiding in the rescue.
"If you keep moving," Jones said, "it's almost impossible to find you."
Officials said the group set out Sunday morning for an annual trek to Henninger Flats, then went through a narrow gorge in Eaton Canyon to the picturesque waterfalls.
Jones said the team was experienced and prepared, outfitted with backpacks, first aid kits, extra clothing, water and food.
Hikers who reach the first set of waterfalls have long made a sport of scaling the canyon walls that reach up behind the 40-foot falls and bathing in its cool waters. The Associated Press reported that the church hiking group was rappelling down the walls behind the falls, and Altadena Mountain Rescue Team training officer James Moussally described the group as "canyoneers," hikers who work their way deep into a canyon and then descend by rappelling.
"I think it's a matter of maybe they weren't quite prepared for it to take as long as it did," Moussally said.
As the group began its descent, authorities said, the darkness closed in quickly and they decided to make a camp on a steep hillside. They were found about 10 a.m.
Officials said it didn't appear that the group had traversed into the canyons' upper falls area, a stretch of wilderness that was closed in July after years of treacherous and expensive air and ground rescues. The hike to the second waterfall is considered risky for less experienced hikers.
In July, two women had to be airlifted from the area after tumbling down the craggy face of a canyon wall near the upper falls. One slipped nearly 30 feet down a mountainside before her leg caught in a tree.
Days later, Angeles National Forest officials closed the area above Eaton Canyon's first waterfall — a steep and perilous climb over crumbling granite to another fall. Hikers who violate the restriction risk jail time and fines.
In 2012, there were more than 60 rescues near the upper falls. Five people have died there since 2011.