Hydro-Quebec DH8D at Montreal on Apr 9th 2014, cargo door open

A Hydro-Quebec de Havilland Dash 8-400, registration C-GHQL performing flight 0Q-170 from Montreal,QC to Quebec,QC (Canada) with 14 people on board, was climbing through 16,000 feet out of Montreal when the crew declared emergency reporting an open cargo door indication followed by slow depressurization of the cabin. The aircraft landed safely back to Montreal 18 minutes after departure.

The Canadian TSB reported the cargo door had not been locked properly.