VERLOT — One person was killed and at least five others were injured Monday evening after a collapse at the mouth of the Big Four Ice Caves, about 12 miles east of here.

Authorities believed all of the survivors had been rescued. A recovery effort was expected to resume at daybreak Tuesday for the body of the victim still inside the cave.

Survivors flown by helicopter to Harborview Medical Center in Seattle were a 25-year-old man in critical condition, a 35-year-old man in serious condition and a 35-year-old woman in satisfactory condition.

Their injuries included leg lacerations, pelvis fractures and shoulder pain, the hospital reported. Tuesday morning, the condition of the 25-year-old man was upgraded to serious. He was in intensive care. The 35-year-old man was upgraded to satisfactory condition and was no longer in intensive care. The hospital said the woman was treated and released Monday night.

Two minors were taken by ambulance to Providence Regional Medical Center Everett. The hospital on Tuesday said they were treated and released.

The ice fall, which included rocks, happened just before 5 p.m. It took roughly 45 minutes for it to be reported due to a lack of cellphone service in the area.

Aerial video showed what appeared to be a great portion of a cave roof collapsed, with rescuers being lowered from helicopters to tend to victims. A multi-agency rescue training session was held at the ice caves in April.

The caves are closed to the public indefinitely. The Mountain Loop Highway also was closed at Deer Creek.

John Scott, of Edmonds, visited the ice caves earlier in the day. He had just pulled off the Mountain Loop Highway and saw a string of emergency vehicles pass. He turned around to see if he could help.

Scott runs Artistic Yard Care, a landscaping business. His rig was equipped with shovels, picks and bottled water. Despite his offer to help, he was turned away.

He stuck around long enough to see two men flown out by medical helicopters. “Both men wore neck braces. It looked devastating,” he said. “I could tell they were both in a lot of pain.

“As soon as one helicopter left, the other landed. The level of emergency medical support was impressive,” he said.

The Monday collapse followed one Sunday, which Sara Soleimani, of Long Beach, California, recorded with a video camera. The video shows an overhang of a cave collapsing. At least four people came out of the cave unhurt.

Soleimani said she wishes she could have posted Sunday’s video earlier. She didn’t get a chance to post it to her You Tube account until about noon Monday. After she did so, she said, she emailed KIRO-TV in Seattle to get the word out.

“I wish people could have seen this sooner, then maybe this could have been prevented,” she said. “It is very shocking that this happened just a few hours after.”

Sunday’s collapse happened about 3 p.m. “When I saw it happen, it was the right side that collapsed,” and it looked like the left side was going to soon follow, she said.

She and her family were scared but stayed by the caves as other hikers arrived.

“People told me they heard the sound when they were 10 minutes away,” she said. “I showed them the video and they didn’t go inside.”

Tracy M. O’Toole, a spokeswoman for Mount Baker-Snoqualmie National Forest, said multiple warning signs have been put up in the past year to indicate the danger.

The ice caves have long been a popular place for hikers. It’s a short, flat trail along the Mountain Loop Highway in Mount Baker-Snoqualmie National Forest. The ice is formed by avalanches that roar down the mountain’s north face during winter and spring. Most years, one or more caves form as the ice melts.

The temperature in Verlot on Monday reached 87 degrees, and this year’s heatwave and low snowpack have broken records. Recent hiking reports described the caves as constantly melting, with water running off calved-off sections.

The last fatality at the ice caves was 11-year-old Grace Tam, nearly five years ago. In 1998, a Bothell woman died when part of an icy arch near the cave entrance collapsed on her. Two boys survived being caught in a 1996 collapse. Before that, two men exploring the caves were trapped when the entrance collapsed. They managed to dig themselves out with their pocket knives.

Grace was sitting on a flat rock about 20 feet from the ice when she was killed by a bouncing chunk of ice. She was on a family outing with her parents John Tam and Tamami Okauchi. Grace never went inside the caves and the family believed they were sitting a safe distance away.

After her death, her family sued the Forest Service, in part saying they wanted more warning signs installed. The suit was dismissed in court.

The Forest Service in 2010 considered fining people who entered the caves. There are no rangers stationed at the ice caves, but there are multiple warning signs. On any given day people can be seen scaling the ice walls and venturing through the caves, often with children in tow.

The Tam family has hiked the trail to the foot of the ice field every July 31 since Grace died.

“Every year we see someone go inside,” Tam said Monday afternoon, a few hours before the collapse. “It breaks our hearts to be honest with you. I don’t understand. I really don’t understand.”

The Tams don’t want anyone else to suffer as they have because of the melting caves. Last summer, the Marysville couple and the Forest Service installed a plaque with Grace’s photo on it along the trail. It is meant to serve as a warning to stay away from the caves.

The last paragraph on the plaque describes the danger of the inviting spot: “The Tam family wants you to be aware that this is a beautiful but always changing environment. They hope that you enjoy the ice caves and Big Four Mountain only from a distance.”