In a tragic incident, a six-year-old girl has died after getting entangled in a swing set at her school.

The incident happened at the S Christa McAullife Stem Academy in Greeley, Colorado, on 5 December when Brooklyn Thill was playing outside her school and accidentally got stuck in a swing set meant for disabled children. She died three days later at Children's Hospital Colorado, the Daily Mail reported.

An investigation has been launched to find the cause behind the child's death, but police have not yet been able to determine how she got caught inside the set, which has now being removed by the school's staff.

Announcing the little girl's death, her mother Nathalie wrote on Facebook: "Our hearts are broken. Our princess Brooklyn, is an angel now." She also shared a picture of herself holding Brooklyn in her hands.

Students and teachers at Brooklyn's school joined other community members to hold a "Pink Princess Day", in her memory on Tuesday (12 December).

Jamie Mould, a parent of one of Brooklyn's first-grade classmates, said, "It was a sea of pink. There were pink socks, pink bow ties, pink jackets, pink backpacks, princess dresses. She was a friend of my daughter's and it hits really close to home."

The S Christa McAullife Stem Academy has also made a makeshift memorial at the fence of the school, FOX31 Denver reported.

A GoFundMe page has been created to help the girl's family, who is burdened with the medical bills incurred from the helicopter flight from NCMC to Children's Hospital as well as Brooklyn's stay in an intensive care unit.

"The few days we were at Children's Hospital in Denver gave us the opportunity to say good-bye, but also lead us to our financial need. While the miracle we prayed for did not happen, we are thankful for the time we had, the precious memories of our beautiful girl, and look forward to when we will see her again!' they said in a description on the page," Brooklyn's parents said in the fund page.