Lauren Bullock has been described by devastated friends as a beautiful soul, a shining light and an angel.
The 17-year-old from Donaghmore was a student at St Patrick's College in Dungannon.
Friends and family took to social media to express their shock and heartbreak over the death of the popular young cheerleader.
Lauren's cousin Andrew McAnallen wrote online: "My heart is broken about what happened last night," he wrote.
"My cousin was out celebrating St Patrick's Day in Cookstown, and fell victim to an unfathomable tragedy. My family and I just can't believe it. She was a warm, caring girl with everything still ahead of her."
St Patrick's College principal Catherine McHugh (above) said she was a gifted student.
"She was a leader among her peers and a quiet, strong and loyal presence," she said.
"A treasured friend and capable young lady with a bright future."
The school also posted a poignant tribute to their "shining light" on their social media pages. "A daughter and sister," they wrote.
"Our treasured friend. Our gifted student. Our young person of truth, faith, and integrity. Our shining light. Our Loss. Rest in Peace, Lauren."
Lauren was a successful senior athlete in the Euphoria Allstar Cheerleading NI group. Her devastated team-mates paid an emotional tribute to their "angel". "My heart is broke writing this," one wrote. "You were the most down-to-earth, beautiful soul.
"You were an incredible cheerleader and were the backbone of our team. I honestly cant put into words how much you will be missed. Thank you Lauren for giving me the pleasure of coaching you all this time. We love you Lauren, you're now shining over us all. We will never forget you. The brightest Purple star in the sky. Our angel."
Heartbroken friends described Lauren as beautiful and "a lovely girl, always smiling and a great friend".
Fellow cheerleader Mary King said: "I have absolutely no words. Such a tragedy within our sport and team."
Friend Tegan Mullan said she was "absolutely heartbroken and lost for words".