A mother and her unborn child were killed and her husband is fighting for his life after a motorbike crash that almost orphaned their son.

Kristin Cheyenne Moon Martinson, 28, died when the bike she was riding on crashed at an intersection in Piedmont, South Carolina, about 11.30am on Tuesday.Cheyenne’s husband Peter Martinson, who was driving, was severely injured and spent the past few days in and out of consciousness.

Family said he had a skull fracture, bleeding and swelling around his brain, multiple facial fractures, and both of his arms were broken.

Kristin Cheyenne Moon Martinson, 28, died and Peter Martinson was severely injured when their motorbike crashed. Their son Bentley, 2, was not with them

Cheyenne was six months pregnant and her unborn daughter was also killed. They were pronounced dead in Greenville Memorial Hospital at 8.30pm

He is in the ICU, heavily sedated and intubated, after undergoing multiple surgeries to keep him alive, and put metal rods in his broken arms.

Martinson is stable but still in critical condition, and the extent of his injuries and prospects of recovery are still unclear.

Cheyenne’s mother Becky Moon said he was showing signs of improvement and reflex testing showed promise.

‘He is still unconscious, he knows nothing about losing his wife, and unborn daughter, and he is fighting for his own life,’ she said.

‘The family is waiting for Peter to wake up to make final arrangements for our daughter. Please keep praying for Peter, because Bentley needs his daddy!’

Martinson’s friend Amber McCoy said he was aware enough to be annoyed by hospital staff.

‘He gave a peace sign and tried to square up with the nurse (in true Peter form). He was able to look at me and he acknowledged who I was,’ she said.

Cheyenne’s husband Peter Martinson, who was driving, was severely injured and spent the past few days in and out of consciousness

The couple have a two-year-old son named Bentley, who was not on the bike

Others mourned Cheyenne online, including Sommer Lawton who said her death ‘feels like losing a part of myself’.

‘You weren’t just my best friend, you were my chosen family for 15 long years, my safe place, my laughter on the hard days,’ she wrote.

‘Your presence lit up every room and every moment we shared is a memory I’ll hold onto for the rest of my life.

‘I don’t know how to say goodbye, so instead, I’ll just say thank you, for everything. I’ll carry you with me, always.’

A fundraiser to support Bentley and for Martinson’s medical bills has $3,600 in donations so far.

The families have not made any funeral arrangements for Cheyenne as they wait for her husband to wake up and be involved in the planning.