How disasters, calamities and sicknesses like coronovirus are compatible with Allah's mercy?

Ilnesses like coronavirus are something good in reality.
How disasters, calamities and sicknesses like coronovirus are compatible with Allah's mercy?
How disasters, calamities and sicknesses like coronovirus are compatible with Allah's mercy?
How disasters, calamities and sicknesses like coronovirus are compatible with Allah's mercy?

mercy?