This is the final photo four high school friends took together before two of their lives were tragically cut short.

Caroline Kam, from Memphis, Tennessee, snapped the selfie with Maddie Kruse, Rachel Lynch and Kara Holden as they headed to the beach to celebrate her birthday at the weekend, WMC reported.

It was the last time the friends would be pictured together; around 6am on Sunday, as Caroline's grandmother drove the teenagers, a car driven by Melandus Penson smashed into their vehicle.

Penson, who had allegedly been drinking, is believed to have hit the back of their car, sending it into a pole. Maddie and Rachel, both 17, were killed.

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Final moments: Caroline Kam (front right) snapped the photo of her friends Kara Holden ( left), Maddie Kruse (in orange) and Rachel Lynch (back right) before they were hit by a driver. Maddie and Rachel were killed

Caroline was knocked unconscious, her father David Kam told WMC, but when she came to, she called 911 and then her dad.

'I thought the wreck wasn't that bad, because she was talking to me in an ambulance,' Mr Kam said. 'I thought she was in the front seat with the drive. Of course, when I got to the hospital and the doors went open, I see her laying there strapped down with her cellphone. I just couldn't believe it.'

She then called her friends' families 'with no concern for the shape she was in,' her dad said.

She needed stitches for cuts while Kara suffered broken ribs and a broken collarbone, Fox13 reported. When Caroline was released from hospital, she immediately went to see Kara, who was being treated at LeBonheur Children's Hospital.

The condition of her grandmother is not known.

Loss: Rachel Lynch, left, and Maddie Kruse, right, were both sitting in the back of the truck and died

Arrested: Melandus Penson, pictured in a mug shot, has been charged with two counts of DUI death

Penson, who has previous DUI convictions, has been charged with two counts of DUI death and two counts of bodily injury. He is being held on $3 million bail in Marshall County Jail.

He has been repeatedly arrested for drink driving, according to Fox13, including three times in a two-month period in 2014.

The channel reported that it is possible for a driver to get as many as six DUIs without getting a felony conviction.

'We wished they would have never encountered this guy, but thinking now, if they didn't encounter this guy, he was driving a long ways,' Mr Kam said. 'He could have done that to anyone.'

Following the tragedy, more than 1,000 classmates, friends and family members gathered at the chapel at girls' school, Briarcrest High, for a memorial service.

Remembered: Students and families paid tribute to the killed girls at a balloon release this week

Afterwards, friends and members of the student council released balloons.

Both girls were remembered as standout students; Maddie was a talented sports player, who was part of the school's golf and softball teams, while Rachel was involved in theater at the school.

'Family is the most important thing to me, so when I have to leave them, it breaks my heart,' Maddie wrote on Twitter last summer.

Caroline, who survived the crash, wrote on her Instagram page: 'Maddie and Rachel were the best friends anyone could have. My heart aches for them and their families. I miss you so much. I'll never forget.'

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