Nearly six months after losing their teenage son, his parents still don't know exactly what happened.

Kyle Losse, 14, was active and athletic before his death in January. The Delta, B.C. teen was a rising star in Tsawwassen baseball, with 145 at-bats and 92 RBIs in his most recent season. He batted .600, had 18 home runs and struck out only seven times.

His father and coach, Brian Losse, described him as an athlete who wanted to give his best at every moment.

But on Jan. 20, the boy considered a picture of health suddenly collapsed in his home.

He was taken to the emergency room at Delta Hospital, but was discharged after spending eight hours at the facility.

A few hours later, he was rushed by ambulance to BC Children's Hospital, where a CT scan revealed extensive brain damage.

"I think there needs to be some changes to what the criteria is for CT scans," Kyle's stepmother Niki said.

"When I look back at Kyle's chart and when I see what was written in his records, I think I would have done something more."

Niki and Brian said they're worried it could happen again.

Two mothers have come forward with similar stories, after hearing about what happened to Kyle. 

Speaking exclusively to CTV News, Nona Gallagher and Denise Turner said their daughters went to Delta ER multiple times with severe head pain. Neither received a CT scan until just hours before they each died of brain tumours.

Fraser Health is standing by the care at Delta ER, but launched an investigation into Kyle's death back in January.

"When we see a young person who dies and has been in one of our facilities, we do everything we can to look at the case and find out what happened and see if we can make improvements in care if possible," said Dr. Neil Barclay, regional medical director of emergency medicine.

In 2014 – after the deaths of Nona's and Denise's daughters and before Kyle's – Fraser Health implemented a new system for reviews.

"We look at those cases and see if there are learnings or systematic changes that we can make,” Barclay said. “And once again, we feed it back to the physicians that were involved so that they know what's going on.

But still, Kyle was sent home without a scan, a decision his parents have trouble understanding.

"When we had the meeting with Fraser Health they said they wouldn't have done anything differently, that they provided all the care that they needed to do," Brian said.

They're still waiting for the coroner's report nearly half a year after the death of their son, but received a preliminary version this week. The report showed no substances like drugs or nicotine in his system.

They'd initially thought he'd been vaping before his collapse, but now it seems he was not. Niki said it leaves them with more questions than answers.

A full report is expected this summer, but the Losses say they've been able to find strength in the baseball community in the months since.

"Just recently we had our opening day ceremonies and they retired Kyle's number, 14, from Tsawwassen baseball," Niki said.

"No one will ever wear his number again. So that was really emotional, something we weren't expecting."

Brian is still coaching, and while it's hard not seeing Kyle on the field, it's helping him cope with the loss of his son.

With a report from CTV Vancouver's Breanna Karstens-Smith