HALIFAX -- It has been an excruciating two days for Justin Zahl as he awaits word on what happened to his parents after a mass shooting in Nova Scotia. 

At least 18 people were killed in the weekend rampage and investigators fear that number will rise as they probe 16 crime scenes in the province.

The crime scenes include five structure fires where RCMP believe more victims may be found.

John Zahl and Elizabeth Joanne Thomas had a home along Portapique Beach Road in Portapique, N.S. -- the small community where the tragic events started to unfold late Saturday evening. 

Zahl says hasn't heard from his parents since 6 p.m. Saturday.

His parents had a routine -- his mom would always send him a good night text. But that night, there was no message, and he hasn't received one since.

He fears the worst.

It wasn't until he saw some photos on social media when he realized his parents' home had been burned to the ground.

Police later confirmed the house is gone. Zahl assumes his parents were in the house -- but nothing is confirmed at this time.

"(It will) maybe take a week or so to figure out the identities of the people in the house," Zahl said. "I want to put my faith in the system, but it's hard to."

He says he is searching for dental records to give police, and then there will be more waiting for final answers that could confirm his worst fear.

With files from CTV Atlantic's Marie Adsett.