06/19/2015 05:00 EDT | Updated 06/18/2016 05:59 EDT

Veronica Park's family pushing for answers about how she died

Patricia Park was celebrating her granddaughter's first birthday when she heard a knock at the door. She opened it, and a courier asked her to sign for a box of her dead sister's clothes and possessions. 

"All of her belongings were sent to her [from the Correctional Service of Canada]. There was no phone call or email stating that it was going to be sent," explained Marian Park, another sister.

Veronica Park was the youngest of the three sisters, and died while in custody at the Nova Institution for Women on April 24.

Since that time, her family and CBC News have tried unsuccessfully to learn details about about Park's death from uncooperative Correctional Service of Canada officials.

"We would like to know what caused our sister to die," said Marian Park.

The sisters and their mother Annie had spent days trying to learn what happened, when tragedy struck again. 

"We laid our sister to rest on the first of May. On the second of May our mom went into cardiac arrest," said Marian.

'This little boy has faced a lot of loss'

Through all this heartache, the hardest hit family member might be Veronica's young son, Cody.

His father died of a terminal illness on April 8, his mother died while in custody on April 24, and his grandmother was taken off life support May 11.

"This little boy has faced a lot of loss," Marian said. "He deserves to have answers."

The Correctional Service of Canada maintains the family must file an Access to Information request to learn any more information about Veronica's death. 

"Why won't they release it to us?" Marian said. "Haven't we been through enough?"