So, an R0 number (pronounces R-nought), is the average number of people one person who is infected with a virus will spread it to. The R0 is 2.5-3. So if you have a group of 20 people, they could infect between 50 and 60 people. Those people, on average, would then infect between 125 and 180 people. Those people would then infect between 313 and 540 people, and so on. With a mortality rate of between 1 and 3%, that means with just 3 steps, you are looking at between 3 and 5 people dead, all because some people wanted to have a party. Because the infectious period for COVID-19 lasts 5 days, this means that in just two weeks we could see that many deaths, and the numbers of infected are compounding. So, if 20 people gather, then in 30 days you could see as many as people 437 dead.