10km/h is a regular jogging pace. For an amateur, not a professional runner.

Anyone can die anywhere, you can die of an infection because of a papercut, but come on. 10km/h is not a dangerous speed.

How fast do you normally walk? 3m/s divided by five is around 60cm/s or about 2 km/h, that's pretty slow. I walk at around 5 mph or 8 km/h, although that is a little faster than most. I think average walking speed is normally about 5 km/h so this is really only twice walking speed at best...

you mean, the same as if you trip while walking, hit your head on the pavement and die?

pretty much, but at least you don't have 4 wheels to slide from under you as you try to keep your footing :-)