The culprit(s) targeted northbound packages when they gained entry into the building sometime between 11:30 p.m. on Jan. 14 and 5 a.m. on Jan. 15.
Stacks of mail had accumulated in the depot due to bad weather in the Kivalliq region.
While cigarettes and liquor appear to have been the main targets, a large number of ExpressPost, Priority Post and regular parcels were either stolen or destroyed.
They also vandalized the facility, spreading flour and eggs on top of the scattered, ripped and destroyed parcels.
The matter is under investigation by Churchill RCMP, who are being tight-lipped about the crime.
Const. Chad Butler of the Churchill detachment wouldn't place a total value on the damaged and stolen mail.
"I can't disclose any information on what was stolen or how entry was gained into the facility at this time," said Butler.
"There was security in place at the site, but I'm not at liberty to disclose the type of security at this time.
"We're following a number of leads, but I can't give a time frame as to when we expect to lay charges."
Calm Air president Gary Beaurivage said the break and enter was the first time anything of this magnitude had ever happened at the cargo facility.
He said the incident took the company by surprise due to the fact the cargo depot is located within a tightly secured area of the Churchill airport.
"We're quite concerned over this matter, of course," said Beaurivage.
"The fact these people were to able to gain access to such a secure zone is quite upsetting.
"There was an awful lot of cargo in that facility and the smashed eggs and flour created a very large mess.
"In all honesty, however, there was a lot of product that remained undamaged and we're grateful for that, at least."