Officials at Unalaska's Fire and Public Safety Departments said they couldn't determine the cause of Tuesday's avalanche that killed 21-year-old snowmachiner Trey Henning.
But according to Acting Fire Chief Mike Hanson, there was significant new snowfall on the mountain near the Overland Drive quarry, where Henning was riding alone at the time of the accident.
"There was a fresh layer [of snow] before the avalanche, with significant wind influence at the top of the mountain," said Hanson. "Just looking at the beginning of the slide, on the edges, it was roughly one to three feet deep. Then towards the middle, it was up to 10 feet."
After the avalanche, as both Good Samaritans and first responders arrived on the scene, he said Henning's snowmachine was still visible, and he was found about eight feet away, buried beneath six feet of snow.
While officials were unable to determine how long Henning was buried, Hanson said the full recovery effort took about one hour and 15 minutes for 15 fire and EMS responders, 10 police officers, and 11 Good Samaritan snowmachiners.
"Once we got the rider out, we started life-saving measures," said Hanson. "We continued those life-saving measures, put the rider in a sled, brought him down the hill, put him in the ambulance, and the ambulance took him to the clinic. The clinic continued those life-saving measures that were eventually unsuccessful."
Henning was a mechanic at the city's Department of Public Works and a 2017 graduate of Unalaska's high school. A GoFundMe page has been set up online to help raise money for his family and offset travel, burial, and memorial costs.
Hanson said the state medical examiner will conduct an autopsy before Henning's body is released to his family.
"We'd like to give our condolences to the Henning family and let the community at large know that we're thinking about them," he said. "Anything we can do to help, just let us know."
Hanson also reminded Unalaskans to use extreme caution in the backcountry and potential avalanche areas. He said anyone heading out for winter recreation should carry communication equipment, as well as a beacon, shovel, and snow probe, along with the knowledge to use them.
Meanwhile, Interim Police Chief John Lucking said one police officer sustained a back injury during the avalanche response. He was taken to the clinic and is now recovering at home.
Lucking said all first responders are receiving in-house stress debriefings in addition to outside help from counselors at the Aleutian Pribilof Islands Association (APIA).
"Grief counseling is right there," said Lucking. "Delta [Bedard] from APIA was actually at the scene with the [Henning] family providing support, and that was an amazing thing. It's another example of how this community rises to help each other get through what has been one thing after another."
Henning's death is the latest in a string of fatalities of young, longtime members of the community.
For grieving Unalaskans, counseling and mental health resources are available through APIA. Unalaskans can call the help line at 359-2743 to speak with a provider over the phone or make a face-to-face appointment.