A group of seven NOLS (National Outdoor Leadership School) students backpacking during an independent travel day during the last days of their course in Alaska came across a mother griz and some cubs. Four students were attacked, suffered injuries. They were in the Talkeetna wilderness.
The teenage students were armed with bear spray and the appropriate emergency protocol, but apparently did not get to use the repellent. Evacs got underway in enough time for the students to reach formal medical care before their injuries worsened.
A number of things are coming into play that make this situation unique in the history of bear attacks. The students were crossing a stream. The odds are very good that the bear did not hear them, a key issue in bear country, even as they were making noise for that very purpose. Thus, they may have startled a mother bear, which almost never ends well.
It was evening, around 8:30. This is when bears become active foragers, more so when with cubs. The kids were probably looking to find camp close to the stream as a water source.
The only way this could have been prevented was by staying home. Given the number of trips and students NOLS leads each year, it has done a remarkable job of keeping its students safe in hostile environments. The School, literally, wrote the book on backcountry travel, safety and injury care. I feel awful for the kids, who just wanted to experience wilderness. The School now has an ugly case study for the upcoming Wilderness Risk Management Conference and hopefully, more information on which to base future bear country travel guidelines.