How many daily dead will create a pile up of bodies?

For weeks already, Italy's structures for dealing with the dead have been under strain. Caskets have had to be stored in make-shift structures, halls, and churches as crematoriums and cemeteries have been unable to keep up with the increased volume in cremations and burials. In early March, satellite images of a cemetery in Iran showed the fresh excavation of burial trenches, presumably to cope with their growing number of dead.

I've kept a morbid eye on the daily death numbers recorded, wondering how many dead, above the normal daily average, does it take to create a crisis in terms of disposing of the bodies?

Let's take Italy. Italy's death rate is around 10 people per 1000 of the population (currently on 10.6/1000). Italy's population is currently at 60.48 million.

Based on this, if 1% of the population are going to die this year through natural causes, illness (excluding coronavirus) and accidents, that's 604,800 people. This is 1,657 people per day in a normal year. Most people will be buried and fewer will be cremated. The country's infrastructure can handle these numbers, and, presumably, have capacity for additional numbers on busy days.

2017 figures showed that only 24% of the dead in Italy were cremated (approx. 400/day countrywide). Italy's current cremation rate is not listed on Wiki's cremation rate page, but it is probably similar or less than that of Spain at 35-45% (cremation is on the rise).

With coronavirus, the crematorium in Bergamo, the hardest-hit city, is currently experiencing 50-60 cremation requests for every 100 dead - this explains the overload on capacity and why bodies are being transported to other towns for cremation.

Cremation is the preferred method for dealing with someone who has died from coronavirus as you can be sure that the 950°C furnace temperature will incinerate the body as well as every trace of the virus it contained.

Bergamo's crematorium is running 24 hours a day, seven days a week and they cremate 24 bodies a day, which is more than double their normal maximum.

I read online that the cremation process takes two to three hours per body and that only one body is incinerated in each oven at a time (because of the law and space inside the furnace - same in South Africa). Crematoria would have more than one oven - maybe three or four of them.

Looking at Italy's coronavirus numbers... Since 10 March 2020, Italy has not reported a daily death count below 100.  They have  had more than 600 coronavirus deaths a day for the past three weeks with many of these days logging over 750 deaths. This would be on top of the 1,600-odd usual daily deaths.

If 1,200 -1,400 of these are to be cremated and at least 1,200 to be buried each day (mostly in Northern Italy), infrastructure far greater than what currently exists is needed. There are 79 crematoria in Italy. They would all need to do at least 15 bodies a day to keep up - and the small-town ones would not even have this capacity. This explains the three-week waiting list (and limited cold storage!). With every day, the numbers of caskets in the queue just keeps building.

In the USA, the average cremation rate is around 53%. This varies widely from 20% to 76% depending on the State (New York is 40%). At approximately 2.8 million deaths/year (~7700/day), the US should have better capacity to absorb the >1500 daily coronavirus deaths than other countries because their infrastructure is geared for a higher number of cremations overall. Nonetheless, it is still up to 20% more bodies to deal with each day!

South Africa's population is 57.78 million and our death rate is 9.5/1000. That's 1500 people/day. In Cape Town, the cremation rate is 40%. This will vary around the country with varying preferences for cremation or burial. My search has revealed no other numbers for South Africa with the exception that we have 33 crematoriums that are already overburdened with some these facilities in frequent need of repair. Available land for burials is already limited.

Any day-after-day, significant increase in the numbers of daily dead will put any country's infrastructure under strain. I can see why grave trenches are the most feasible and timeous method of dealing with a pile-up of dead. But, in the case of coronavirus it is not the wisest method of disposal because of the uncertainty around how long the virus may linger. That's why cremation remains the recommended and safest method to ensure that all trace of the virus is incinerated along with the body.