What type of bias is used when death toll numbers are inflated in order to make a disaster seem more spectacular?

This type of bias is a bias of statistics and crowd counts.

A bias is the intentional or unintentional sense for having a preference to one particular point of view or perspective. In this type of bias, numbers are often inflated to make a disaster more spectacular, and therefore worthy of reading about.

Example of such – 75 people were injured in the car accident, can be the same news as only 5 were injured in the accident. This is usually done to make a news story seem worse or better than it actually is.
Hope this helps.