A 15-year-old victim of Wednesday's high school massacre in Florida held the door open for classmates as they fled the gunman before he was killed.

Peter Wang is one of the 14 students at Marjory Stoneman Douglas school in Parkland, Florida, who were killed by gunman Nikolas Cruz.

Peter's grieving cousin Aaron Chan was also in the school at the time and saw him holding the door for classmates, dressed in his grey ROTC uniform.

He carried on running and it was the last time he saw him alive.

'He wasn’t supposed to die. He was supposed to grow old with me,' Aaron told First Coast News.

Peter Wang's cousin told local media he last saw him holding the door for fellow students at the school on Wednesday as they fled the gunman. Peter, 15, (above in his ROTC uniform) was confirmed dead on Thursday

His best friend Gabriel Ammirata told The Miami Herald he was a 'funny, nice and great friend'.

'He's been my best friend since third grade,' he said.

Peter's parents, who are Chinese and can only speak Mandarin, struggled through the chaos on Wednesday by relying on neighbors and friends to translate for them.

They, like other parents, rushed to a hotel which was chosen by authorities as a place for parents who hadn't heard from their children to gather and wait for news.

Heartbreaking photographs from the room show the families waiting in anguish to learn if their child made it out alive.

The other thirteen killed were Jaime Guttenberg, 14, Nicholas Dworet, a high school senior, Martin Duque, 14, Meadow Pollack, 18, Cara Loughran, Alaina Petty, 14, Joaquin Oliver, 17, Luke Hoyer, 15, Alyssa Alhadeff, 15, Gina Montalto, 14, Carmen Schentrup, Alex Schachter, 14, and Helena Ramsey, 17.

Peter's friends said he was 'smart and funny'. He had been missing all through Wednesday after the shooting

Peter's parents are Chinese and speak little English. They relied on a neighbor and friends for information and gathered with other distraught parents at the Marriott hotel where they sat waiting for news later into the night. They were given pizza and water to sustain themselves

Peter is pictured with his mother. He and thirteen other students were shot and killed

Track coach Aaron Feis, 37, geography teacher Scott Beigel, 35, and athletic director Chris Hixon, 49, were also all killed.

They all died heroes, protecting groups of children from the bullets.

Fifteen others were injured.

Gunman Nikolas Cruz is in custody and has been charged with 17 counts of murder.

His public defender Melissa McNeil offered him support on Thursday as he was arraigned and put her arm around him as he stood to face the judge.

She later told reporters outside the courthouse that he was remorseful: 'He’s sad.

'He’s mournful. He’s remorseful.

'He is fully aware of what is going on, and he’s just a broken human being,' she said.

Gunman Nikolas Cruz is in custody and was been charged with 17 counts of murder on Thursday. He is pictured with his public defender who comforted him in court and later said he was 'remorseful' and 'a broken young man'

Youngsters hug each other at the vigil for the victims of the Florida High School massacre

Jalina Kohen (left) and Brianna Hall (right), join hundreds of community members at the prayer vigil