At the center of a terrifying coronavirus surge, 242 patients lay in row after row of beds under the soaring metal beams of a decommissioned Volkswagen factory.

Workers at the vast field hospital could provide oxygen and medications, but there were no I.C.U. beds, no ventilators, no working phones and just one physician on duty on a recent Sunday — Dr. Jessica Du Preez, in her second year of independent practice.

In a shed-like refrigerator behind a door marked “BODY HOLD,” carts contained the remains of three patients that morning. A funeral home had already picked up another body.

On rounds, Dr. Du Preez stopped at the bed of a 60-year-old patient, a grandmother and former college counselor. Her oxygen tube had detached while she was lying prone, but the nurses had so many patients they hadn’t noticed. Now, she was gone.

As two porters placed her corpse in a bag, a worker peeked through the door to tell them another patient, a 67-year-old diabetic man, had died.

Meanwhile, the condition of a teacher in her 50s was deteriorating. Dr. Du Preez tried to find I.C.U. space for her elsewhere in the city, to no avail. She called the teacher’s husband, who asked what he could do. “Not much,” the young doctor responded.

“Shame,” she said again and again that day.

For hours, the alarm on the teacher’s bedside monitor bleated. Her oxygen level was dangerously low, her pulse racing and her blood pressure soaring. Still, she remained conscious, saying she could not breathe. That evening, she died alone. A book, “A Heartbeat of Hope: 366 devotions,” lay on her bedside stand alongside a pair of reading glasses.

When the pandemic began, global public health officials raised grave concerns about the vulnerabilities of Africa. But its countries overall appeared to fare far better than those in Europe or the Americas, upending scientists’ expectations. Now, the coronavirus is on the rise again in swaths of the continent, posing a new, possibly deadlier threat.