Update 08/18/2015 regarding the paragraph below that says bison haven't been killed as a result of run-ins with tourists: The Times reports that Yellowstone National Park is now killing bison, just as it killed the grizzly bear involved in Lance Crosby's death.

Update 08/13/2015: On Thursday, a day after an autopsy found that Lance Crosby didn't die of other medical reasons, park biologists killed Blaze, a 20-year-old grizzly sow who had fed on Crosby's body.

After a Yellowstone National Park seasonal employee recently died after being attacked by a grizzly bear, some are rallying against a park decision to euthanize the bear.

On Friday, Lance Crosby, 63, of Billings was found dead a half-mile off the Elephant Back Loop trail near Lake Village on the northwest shore of Yellowstone Lake.

On Wednesday afternoon, an autopsy confirmed that Crosby hadn't died of any other medical condition, so it's likely he was killed by a bear, according to the Associated Press. An earlier National Park Service statement said wounds on Crosby’s arms appeared to be defensive.

Although an investigation continues, evidence indicates that bears partially consumed Crosby’s body and then covered it over so they could return later.

Crosby, 63, had worked five seasons in the park for Medcor, which staffs three urgent-care clinics.

In three updates since the incident, the NPS has repeated that Crosby was an experienced hiker. But Crosby was not carrying bear spray when he disappeared.

After collecting samples from the body and the scene, park employees trapped a sow and a cub. They captured a second cub on Tuesday.

YNP superintendent Dan Wenk said the bears would be killed in the interest of public safety if DNA samples revealed they had eaten part of Crosby’s body. The cubs may be spared if a zoo is willing to take them.

His decision has sparked a pushback from wildlife advocates, who argue that Crosby didn’t take proper precautions when he was hiking alone without bear spray. They say the park's mission is to preserve wildlife so animals should not have to pay for the mistakes of humans.

One man, Richard Spratley, launched one of two online petitions that ask Wenk to spare the bear identified as “Blaze,” and relocate her and her cubs to someplace else in the park.

The petition statement says, “It seems very clear from the media and park reports that this was a sow protecting her cubs. Because this hiker was negligent in following basic rules in grizzly territory (no bear spray, no bells or noise makers, hiking alone), these bears may pay the price. They were in their own natural habitat, not invading human habitat.”

Spratley set a goal of 55,000 signatures and it appeared he would reach that by the end of Wednesday.

Another petition on Change.org has gathered 5,600 signatures on its way to 7,500.

With any species, it’s dangerous to get near mothers with young because they are more likely to be aggressive to defend their offspring. If Crosby surprised the sow with her cubs, she would have been reacting in a normal manner if she attacked him.

So far, that argument doesn't appear to have much bearing on Wenk’s decision. On Monday, he told Montana Public Radio that although it was a tough decision, he needed to consider visitor use, enjoyment and safety.

Wenk recalled the blow-back he received from the public in 2011 when he chose not to kill a bear that attacked a hiker.

“For everyone who's advocating for the preservation of this bear, there were an equal number of voices who were basically telling me at that time that bear should be removed,” Wenk told MTPR.

The difference between the situation in 2011 and the Crosby situation is that there were witnesses in 2011. Wenk said he knew why that death occurred and could justify sparing the bear.

Wenk admitted that all the circumstances of Crosby’s death will never be known.

Those protesting his decision argue that the bear should get the benefit of the doubt.

On social media sites, the community of YNP wildlife photographers urged others to call and email Wenk and U.S. Fish and Wildlife Service grizzly bear recovery coordinator Chris Servheen.

On Wednesday, photographers were reporting that the park phone number had either been disconnected or was so busy people couldn’t get through.

Servheen said he’d taken five to 10 calls on Wednesday but couldn’t comment because too much was still unknown.

Grizzly bears are still protected under the Endangered Species Act so killing a bear is normally against the law. But under certain circumstances, the USFWS will authorize killing a bear, so Servheen is working with park biologists

“We’re still working on the details and pulling together the information so there’s nothing to report. It’s still too fresh,” Servheen said.

The Crosby incident is occurring during a summer that has been marked by stories of people being injured after getting too close to wildlife.

More than 3 million people flock to the park each year and many are not familiar with how to behave around wildlife. Few pay attention to the park literature and signs that warn people to stay a safe distance away from wildlife and to carry bear spray.

At least five tourists have been injured this summer because they wandered too close to wild bison, often because they wanted to take a “selfie” photo.

None of the bison were killed as a result, although the park sent hundreds to slaughter during the past two winters in an effort to bring the population down.

Alternatively, one nervous visitor had a hair trigger with bear spray, spraying a very old bear known as “Scarface” as he was limping along near a road.

It’s also a summer that has seen its share of weather extremes.

Unusual long bouts of heat have caused berries to emerge early. That's prompting some to worry that bears will have a harder time finding food as they try to fatten up before going into hibernation.