Police officer saves life of exhausted cancer patient during Las Vegas mass shooting

An off-duty police officer saved the life of a woman with cancer who was too exhausted from treatment to flee gunfire at the mass shooting in Las Vegas.

Cassidy Huff, who had recently finished a course of chemotherapy and was at the Route 91 festival with her mother, collapsed behind a car when she tried to run.

Officer Mitchell Tosti, a member of the Los Angeles Police Department who was at the festival with his fiancee and friends, spotted Ms Huff and carried her to safety.

"She looked tired, so I grabbed her. She was only wearing one shoe when I saw her," he told NBC.

"I was like, ‘I’ll carry you.’ I told my fiancee to grab the mom and follow us."

They fled until they found another officer who drove Ms Huff and her mother Kelley home.

"I think they're amazing and I think it's amazing that we ran into all off-duty police officers," Ms Huff said.

"I wanted to run but my body wouldn't let me. My legs are still really weak so they buckle under me."

Kelley Huff posted a thank you to Mr Tosti and his fiancee in a Facebook post.

"Just as we crossed the street, Cassidy collapsed behind a car, her frail body could not go anymore," she wrote.

"Before I could even try to think what to do next, an off-duty LAPD officer scooped her up in his arms and said to keep running, we can’t stay here.

"His sweet girlfriend grabbed my hand and pulled me along," she said. "What a selfless thing to do."

Mrs Huff said she felt “guilt and physical pain” for the victims of the attack and said she will "pray continually for all those affected by this tragedy."