Question

Natural disaster produced by volcanic activity that has killed more people than lava flows is _____.

Answer 1

The answer to your question would be a mudslide. I am pretty sure that it is right. Sorry if it's not.

Answer 2

Lava flow is actually quite slow, and in most cases you can outrun lava.

What kills people in the case of volcanic activity is either

-Pyroclastic Flows (hot air and ash traveling fast)
or
-landslides or mudslides - those often kill entire villages since they can happen far from the volcano too.