70-year-old nurse who 'went above and beyond' killed in random assault

A 70-year-old nurse who dedicated her career to caring for others was killed in a random assault at a Los Angeles bus stop, officials said.

Sandra Shells was hit in the face while at a downtown LA bus stop at about 5:15 a.m. Thursday, the Los Angeles Police Department said.

Shells fell to the ground and suffered a fractured skull, police said.

She died at a hospital on Sunday, police said.

The suspect, a transient, Kerry Bell, was apprehended about 90 minutes after the assault, police said. Officers found him asleep "a short distance away from the incident," police said.

Police said "Bell struck the victim without provocation and for no reason." Bell does not have a court date listed.

Shells was a dedicated nurse who spent 38 years at LAC+USC Medical Center, according to the hospital.

"She went above and beyond for every patient. Her energy, her empathy, her work ethic, were exemplary," Dr. Craig Torres-Ness, an emergency care physician at LAC+USC, told ABC News. "She embodied what LAC+USC stands for and served her community honorably."

He said young nurses try to "emulate the type of nurse, the type of person, she was."

"We are heartbroken," he continued. "She made people around her better and that will be her legacy."

The hospital said in a statement, "Sandra Shells will forever be remembered for her compassionate care and unmatched dedication to her patients and her community."

"Sandra worked tirelessly and selflessly to keep her patients safe and healthy," the hospital said. "There will never be enough words to express our gratitude for her tremendous work and dedication."

LAPD Chief Michel Moore in a tweet called it a "tragic and senseless murder directly tied to the failure of this Nation's mental health resources."

"We can and must do better," Moore said. "This victim lived her life for others. We are falling short."

LA County Supervisor Kathryn Barger tweeted that she's "calling for a full investigation into the assault."

"It's unacceptable for bus riders to be susceptible to this type of violence," she said. "Our essential workers and the public at large deserve better."