The three cub bears associated with a deadly killing in Soda Butte Campground just outside the Northeast Entrance to Yellowstone National Park were undernourished and still in their winter coats, according to officials in ZooMontana, providing a crucial clue to why a mother grizzly may have gone on a rampage.

"It may be an indication of what happened," Zoo executive director Jackie Worstell told AP. "There's obvious signs of stress and malnourishment. Maybe (the sow) was desperate."

To recap:  A grizzly sow weighing over 300 pounds and her three cubs went to the Soda Butte Campground early Wednesday morning, located seven miles east of the Yellowstone National Park East Entrance past Cooke City, and tore apart a tent containing Kevin Kummer, 48, of Grand Rapids. He was killed in the tent; his body was dragged 25 feet or so and then partially eaten by at least one griz. After that she and the cubs went after two other tents, biting Deb Freele of London, Ontario to the point where she required surgery to repaid the broken bones in her arms; Ronald Singer of Alamosa, Col. was bitten on the calf before fighting off the griz. (Our full coverage can be found in the links at the end of the article.)

Officials had been baffled as to why a griz would have raided a campground; normal grizzly behavior is to avoid humans, especially when cubs are concerned.

The three will remain under observation until the fall. Meanwhile, it's hard to say whether the knowledge that the cubs were malnourished would have had any impact on the decision by Montana Fish, Wildlife and Parks Department officials to put down the mother grizzly: having a sympathetic motivation didn't change the fact she was going after people as food. Still, we're guessing it will lead more to question whether she should have been put down versus sent to a zoo or research facility of some sort.

The above photo shows the grizzly sow before she was euthanized. Courtesy Montana Fish, Wildlife and Parks Department.

RELATED STORIES: Should Killer Griz Been Allowed to Live?; Confirmed: Cubs Involved in Soda Butte Tragedy Headed to ZooMontana; Mother Griz Put Down After DNA Confirmation; Three Cubs May Go to ZooMontana; Third Griz Cub Trapped; Authorities Waiting on DNA Analysis; Griz Victim Remembered as Avid Outdoorsman; Trap Snares Culprit in Soda Butte Killing: A Mother Griz; Why Did Bear -- or Bears -- Attack at Soda Butte?; Bear Kills One, Injures Two in Campground Near Yellowstone

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