Galacticare

This achievement popped as soon as a regular walk-in patient died in the hallways waiting for a room I didn't provide for them. It did not pop from a patient dying as part of an emergency event, or when a patient died from their treatment.

To force this to happen without messing up the campaign or wasting my time, I went into the sandbox map Babylo Getaway, didn't staff the room that my first patient needed, and waited. I did build the rest of the hospital as normal. Once the patient finally died and I got my achievement, I could then continue the hospital to work towards my 5 star sandbox, as this map is very lenient with money, and missing the income from one room for 15 minutes didn't ruin me.

Alternatively, you will probably get this eventually without meaning to, but to do it accidentally you will likely need to be on a more difficult map.

This one seemed to be either a bit buggy or trickier than I thought it would be. I unlocked it in chapter 9, and I remember seeing at least 10 patient deaths in previous chapters.

It doesn't seem that deaths through treatment malfunctions count towards unlocking this. As those were all my previous death causes.

When I unlocked this it was because I had a critically ill patient and for the first time, I didn't prioritise them for a quick treatment or use stabilising agent to boost their health. I simply didn't notice them and they died in the corridor without being treated. Which caused the achievement to pop.