Speaking as someone who rides the STM metro network on the regular, there are a few habits that riders mindlessly follow. Certain actions are just built into your muscle memory, like going through the metro doors as soon as the not-a-robot STM voice announces the station you've just pulled up to.\nBut for some STM riders taking the Orange line on Monday, blindly heading straight through the metro car's doors could have ended in disaster.\nWhy? Because the metro doors opened on the wrong side.\nHeading between Henri-Bourassa and Montmorency station, the metro conductor of this particular train was forced to make an emergency stop at Cartier at exactly 5:22pm, reports Metro. What caused the emergency stop is unknown/unreported, but the result was the same:\nAs the train pulled into the terminal, a misalignment occurred. When the STM driver decided to let everyone out of the metro car, they made a mistake, and instead of opening the doors towards the station's landing, the other doors opened up, giving all passengers an uninterrupted path towards the train tracks.\nThankfully, no one was so zoned out that they Mr. Magoo-style walked right out the doors and fell onto the tracks. One passenger was injured during the emergency braking process, however, causing a brief interruption in the Orange line service, which was later restored at 6:04pm.\nAnd this isn't the first time the metro doors have opened up on the wrong side. Back in 2004, on Monday March 8th, the metro car doors opened on the wrong side between Cadillac and l'Assomption on the Green line. No one was injured, but the same thing happened earlier in the week, with no definite reason disclosed.\nSo what do you do when the metro doors open on the wrong side? Well, what you should be doing every time the doors slide open: Fight every urge you have to walk through those doors like you normally do, take a second, and look before you leap, because you never know where the doors might lead.