A group of more than 75 emergency room doctors, nurses and physicians’ assistants issued an open letter Monday to the people of Miami-Dade County, pleading with them to help stop what they described as a developing crisis like none they have seen before.

The letter was signed by doctors at nearly every major hospital in Miami, including Baptist Health South Florida, Jackson Memorial Hospital and Mount Sinai Medical Center, among others. The physicians stressed that the relatively low number of confirmed cases of COVID-19, the disease caused by the novel coronavirus, doesn’t reflect what they have been seeing at their own hospitals, and that it only reflects a delay in testing. Once testing ramps up, they expect many more cases to be revealed.

They offered some blunt advice to those who still won’t take the public health crisis seriously, urging people to avoid all unnecessary contact with anyone they are not currently living with.