WELD COUNTY, Colo. -- A Colorado family is trying to come to grips with the loss of three loved ones after a mother and two of her children were killed in a car crash.
Sheila Sinclair, 29, and her 6 year-old son Jaxon died instantly in the crash on Highway 52 in Weld County on Friday.
Her 3 year-old daughter Kassidy died at the hospital over the weekend, leaving her youngest child, Bella, as the sole survivor.
"The new normal is going to be really hard. It's going to be a very long, hard journey," said Katie Miller and Stacie Bartolotta, Sheila's sisters.
The Colorado State Patrol said the family ran a stop sign and was hit by another vehicle in thick fog.
The Colorado State Patrol also said Sheila and Jaxon were not wearing seat belts. The family said that's something they were shocked to learn, claiming Sinclair was a stickler for safety.
"I don't know the facts, nor are they important to me at this point," said Sheila's father, Marvin Miller. "Seat belts were so important to her. Jaxon always put his seat belt on and he could do it by himself."
Sinclair's youngest daughter, 18 month-old Bella, survived the crash, although she did break an arm and her leg.
"That's a miracle. It absolutely is," Bartolotta said.
The Sinclairs' extended family now faces the tough task of helping Bella and Sheila's husband, Mark Sinclair, move on and continue living without the rest of their family.
"I'm going to write a book of Jaxon and Kassidy and Sheila and it's going to start, 'Dear Bella. This was your mother. This was your brother. This was your sister," Marvin Miller said.
"Jaxon and Kassidy were inseparable. They were always together. They loved to swim together. They sang together at church. They did everything together," Bartolotta said.
Kassidy's heart was donated Monday to another child in the Denver metro area in need of a transplant. It's a bit of solace for a family facing so much tragedy.
"It means her death wasn't in vain, that through her death other people could live and it's something we'll always cherish," Bartolotta said.
In addition to their grief, the family is also being confronted by thousands of dollars in medial bills and funeral expenses. A GoFundMe page has been created to help raise money for the family.AlertMe