A Northern Ireland teenager has suffered a brain injury after falling from an electric scooter while on holiday in the U.S.

Karmen Curley, 18, from Newtownabbey, Co Antrim was visiting her sister Sian, in Los Angeles, when she suffered the horrific injury after hitting a pothole.

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Sian, who is studying in America for a year, said Karmen came to the US to join her on a two week "trip of a lifetime" around the west coast of California and Las Vegas with Sian's university friends before returning home.

Sisters Sian (L) with sister Carmen (R) before the horror fall. Image: Facebook

Sisters Sian (L) with sister Carmen (R) before the horror fall. Image: Facebook

But Karmen sustained serious injuries last Tuesday, May 28 when she fell from her electric scooter and hit her head having struck a pothole.

The pair had only just rented  the motorized street vehicles, Sian told the Belfast Telegraph

Karmen was thrown over the front of the vehicle and after being rushed to hospital lay unconscious for over eight hours in intensive care and was diagnosed with a bleed on the brain.

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In the fall Karmen also suffered broken bones including a broken collarbone, nose and eye orbital bone, which will require surgery. 

"Traumatizing" seeing sister in "pool of blood"

Sian described the “traumatizing” sight of seeing her sister on the floor in a “pool of blood”.  

“We decided to rent out an electric scooter to venture around the area but after not even one minute, Karmen hit a pothole and flew off her scooter," she said. 

“When I went up to her she was unconscious and in a pool of blood. The blood was pouring out onto the ground, it was traumatizing to watch."

“The ambulance came and she was taken straight to Intensive Care in UCLA Hospital,” Sian said. 

“We have been told that if she gets out, she will need to stay in LA and go for a follow-up meeting before she can fly home to Belfast.”

Both students remain in Los Angeles without any other family to help after their mother, Karen, died suddenly last year. 

Sian said if her mother were still alive, she would be “sorting this all out,” but instead she is "stressed out and confused'.”

Injuries and cost

Karmen remains in intensive at Los Angeles's UCLA Hospital and Sian says she is at her “wit's end” because of the spiraling cost of her treatment.

Having forgotten to buy travel insurance, Sian is desperately trying to raise more than $150,000 to pay for her sister's treatment. 

Read MoreIrishman who suffered severe brain injury in US accident returns to site of crash

"It is $15,000 per day to stay in ICU and that isn't including her medication, scans or needles. I am at my wit's end - I don't know how I will afford this." 

Rental service electric scooters parked in a row on a sidewalk. Image: Getty

Rental service electric scooters parked in a row on a sidewalk. Image: Getty

This follow-up will cost $4,000 alone, so the total just keeps getting more and more."

Go Fund Me page set up to raise money for Karmen's treatment has so far raised nearly $12,000. 

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In 2018, Dr. Tarak Trivedi, an emergency room physician in Los Angeles and co-author of one of the first peer-reviewed studies of scooter injuries counted 249 scooter injuries, more than 40% were head injuries. Just 4% were wearing a helmet.