There was one vid I saw -- probably NYC Chinatown - rare. They fell likely because the virus load ramps up, just like a bad flu that you may have got in the past. I doubt it's death, but still serious. But people in the US are far more likely to seek medical attention than folks in China. Superstition matters too, some of China's (and many countries with traditional thinking) old people don't ever want to go to the hospital because of the thought that they might never get out alive.