Avalanche survivors used this obscure iPhone feature to get help

Survivors of the catastrophic avalanche in California's Sierra Nevada that claimed at least eight lives were rescued after using an emergency feature available on some iPhones.

The iPhone emergency SOS feature allows users to send messages to first responders when they have no cell signal, data or Wi-Fi available. When the avalanche near Lake Tahoe on Feb. 17 hit, six people from a group of 15 survived, but they were stranded amid a fierce winter storm.

The six were rescued from the remote backcountry hours later, and two had injuries that were not life-threatening. Eight people were found deceased, but their bodies have not yet been recovered from the mountain. One skier is still unaccounted for but presumed dead as of the latest update from authorities on Feb. 18.

The lone guide to survive from the company that organized the trip used the iPhone SOS feature to text with the Nevada County Sheriff's Office, which deployed skilled rescue crews to their location. The group also used signals from what's known as an avalanche beacon, which allows skiers to send radio signals so they can be tracked by first responders. The guide relayed to authorities that there were six survivors and was told they needed to shelter in place as best they could.

The SOS feature can be a useful tool in case of an emergency along with tools like a beacon, said Don O'Keefe, chief of law enforcement for the California Governor's Office of Emergency Services.

But not all iPhone owners have access to emergency SOS via satellite. Here's what to know about the feature and how to use it:

What is iPhone emergency SOS? Does my phone have it?

The SOS feature uses satellites to connect users in dire situations to emergency services. If no signal is available, the iPhone will try to connect to satellite. A person needs to be outside with a clear view of the sky and horizon for it to work, according to Apple.

Not all iPhone users will have access to the feature. It's only available on iPhone models 14 or later. In the United States, you'll also need to be running iOS 16.1 or later, but some local emergency numbers will require 16.4 or later, according to Apple.

The feature is free for two years from the point of activation of a compatible model.

USA TODAY has reached out to Apple for comment.

How to use the SOS feature

Using a satellite to text is not the same experience as sending a normal text message. It can take longer and may require you to move around to maintain the connection. That's because "satellites move rapidly, have low bandwidth, and are located hundreds of miles away from Earth," Apple says.

Here's how to use the feature:

• First, Apple says you'll need to be outside with a clear view of sky and horizon.
• Next, you should try to call an emergency number.
• If the call can't connect because you are out of service range, you'll be able to hit the "emergency text" button.
• Next, you'll tap "report emergency" and answer some questions to describe your situation.

Once you're connected, a text conversation will begin with emergency services. They will receive information including the emergency questionnaire, your Medical ID information or emergency contact information if you set them up, your location and how much battery you have left.

Directions on the screen might prompt you to turn in different directions to maintain your connection.

In clear conditions with a direct view of the sky and horizon, a message could take about 30 seconds to send. If there are trees blocking the view, it could take a minute or more. If you're under heavy tree cover, it might not work at all.

Do other phones offer satellite communication?

According to Google, its Pixel 9 and later devices, other than Pixel 9a, also have a satellite feature to use in emergencies when no other signal is available.

Its version, Satellite SOS, works similarly, and requires a clear view of the sky with as little obstruction as possible. The phone will show the option to use the feature if you dial 911 but don't have any connection.

Some mobile carriers also have options for off-the-grid emergency communication. T-Mobile offers T-Satellite with Starlink to stay connected to certain apps when regular signal isn't available.