A supervisor urged surgeons at Columbia University Irving Medical Center in Manhattan to volunteer for the front lines because half the intensive-care staff had already been sickened by coronavirus.

“ICU is EXPLODING,” she wrote in an email.

A doctor at Weill Cornell Medical Center in Manhattan described the unnerving experience of walking daily past an intubated, critically ill colleague in her 30s, wondering who would be next.

Another doctor at a major New York City hospital described it as “a petri dish,” where more than 200 workers had fallen sick.

Two nurses in city hospitals have died.

The coronavirus pandemic, which has infected more than 30,000 people in New York City, is beginning to take a toll on those who are most needed to combat it: the doctors, nurses and other workers at hospitals and clinics. In emergency rooms and intensive care units, typically dispassionate medical professionals are feeling panicked as increasing numbers of colleagues get sick.