CLEVELAND, Ohio — A new study authored by a Cleveland Clinic doctor gives doctors and scientists around the world a look inside how the coronavirus kills.

Before the study was published in the American Journal of Clinical Pathology on Friday, there hadn’t been any published autopsy reports of coronavirus patients. That was a problem. An autopsy allows doctors to closely examine and evaluate a body to understand and identify the cause of death.

“People all over the world were wondering, thousands of people are dying and we have no idea what’s really going on at a microscopic level in their lungs,” Cleveland Clinic lung pathologist and lead author Dr. Sanjay Mukhopadhyay said in an interview Monday.

The study detailed the autopsies of two Oklahoma men: a 77-year-old with a history of hypertension and a 42-year-old man with muscular dystrophy. The doctors who performed the autopsy wore N95 masks, gloves, gowns and other protective gear to protect themselves from the virus. Both men showed coronavirus symptoms, but neither was tested for the illness until after they died. Both tested positive for coronavirus.

Doctors believed that many coronavirus patients were dying of acute respiratory distress. But that was a hunch. In the autopsy of the 77-year-old Oklahoma man, they actually got to see the damage: How the inside of the lung air sacs were coated in what doctors say looks like a thick layer of paint, making it difficult for people to breath.

Their theory was proven out.

Doctors were also able to show that this damage wasn’t caused by the use of ventilators, a point of ongoing conversation in the medical community. The man died without being treated.

“It’s actually proof that the virus itself is causing the damage,” Mukhopadhyay said.

The autopsy of the 42-year-old man was perhaps more interesting. While he had coronavirus, he didn’t die from it. He didn’t have the paint-like coating inside of his lung air sacs. Instead he died of a bacterial pneumonia.

“Therefore, this patient likely died with COVID-19, not from COVID-19. These cases illustrate the challenges that pathologists and the medical community at large will face in determining the cause of death in (deceased people) who test positive,” for the coronavirus the article says.

The autopsies added concrete facts to the medical debate surrounding COVID-19.

Doctors in the larger community have wondered whether the coronavirus causes heart inflammation. The answer from these two autopsies showed it didn’t. Doctors also have theorized that COVID-19 caused widespread blood clots throughout the body. The autopsies didn’t find any evidence of that.

Autopsies could allow doctors to see the problems that virus causes and treat these symptoms with therapies that already exist.

“They’re looking for any sign of things that can be treatable in these autopsy cases,” Mukhopadhyay said.