On behalf of the family, Acosta's cousin shared video with ABC13 of the growing memorial. According to the family, the memorial was held at Taft Elementary, the school Acosta attended before he moved to Washington State.
The 21-year-old lost his life during the Travis Scott concert at NRG Park on Nov. 5.
Initially, authorities needed the public's help to identify Acosta. A couple of days later, Axel's father, Edgar, confirmed to ABC13 that his son was the unidentified victim who had been recovered from Memorial Hermann Hospital after the incident.
WATCH: Astroworld Fest victim traveled to Houston alone from Washington
Astroworld Fest victim traveled to Houston alone from Washington
While authorities have not released Acosta's cause of death, the family's attorney, Tony Buzbee, said he died of crowd rush. A crowd rush occurs when you have a high-density crowd moving in one direction in a confined space.
"The air was slowly squeezed out of Axel, sending his heart into cardiac arrest," said Buzbee. "People trampled over his body like a piece of trash."
The family's attorney also said that first responders did try to restart Axel's heart but failed.
"Axel died on the muddy ground of a concert that he attended for fun. He loved rap music and the lineup, but that love wasn't mutual," said Buzbee.
Axel had just turned 21 in October. He was studying computer science at Western Washington University.