Authorities identified the victim as 57-year-old Brian Matayoshi. Eyewitness News has confirmed Brian Matayoshi works as a pharmacist at the CVS in Lomita.
Brian Matayoshi and his wife Marylyn Matayoshi were hiking on the Wapiti Lake Trail when they encountered a female grizzly bear with cubs.
Torrance resident Kathy Kester has lived across the street from the Matayoshis for nearly 10 years, and like other neighbors, she was stunned by the news of the grizzly bear attack.
"I was devastated. They're really nice people," she said.
"It's very tragic, and I really feel bad for the family. It's really a terrible loss," said neighbor Hugo Rendone.
Park spokesman Al Nash said on Thursday that the mauling was a purely defensive act. Yellowstone authorities said it will not try to capture the bear.
Marylyn Matayoshi told officials she and her husband saw a bear with cubs from a distance and began walking away. When they turned to look again, the grizzly was running toward them.
The Matayoshis began running, but the grizzly quickly caught up with them, attacking the husband and killing him.
Marylyn Matayoshi told officials that he told her to run. She called 911 on her cell phone, and other hikers in the area responded to her cries for help.
Officials said Marylyn Matayoshi didn't see the bear attack her husband. When the bear went for her, she dropped to the ground. The bear lifted her off the ground by the day pack she was wearing and then dropped her.
Park officials believe some 150 grizzlies live in Yellowstone. Still, maulings are rare.
"This is the first time that there has been a bear-caused human fatality in Yellowstone in 25 years," Nash said.
However, the attack was the third in the greater Yellowstone region in just over a year.
Published reports indicate the Matayoshis have been to Yellowstone several times but never before encountered a bear.
The Associated Press contributed to this story.