Problem is we do not know the real death rate. If say 10% of those infected come down with a serious form of the illness and 10% of those die we are looking at a 1% case fatality rate, which may be drastically lowered with modern ICU care. Then it is nothing to really worry about. However if we do have a real case fatality rate of 5-10% regardless of care then we need to take action.
The current rate of fatality on reported cases only is 3%.
Enough to crush every healthcare system in the world.