Four questions the US must answer concerning COVID-19

Third, why did the US shut down the Army laboratory at Fort Detrick that studies deadly infectious materials?

Reports show that the US' main biological warfare lab had been ordered to stop all research into certain biological agents and toxins for security reasons in June 2019, but no detailed reasons have been offered.

Coincidentally, shortly before the lab was shut down, a large number of people became ill with respiratory symptoms, ranging from a cough to pneumonia, in two nursing homes in a nearby county in Virginia.

As of August 27, 2019, 215 possible cases of severe pulmonary disease, reportedly associated with the use of electronic cigarette products, had been reported to the CDC. All patients described in these reports have had ground glass opacities revealed on their chest tomography scans. Relevant infections had been surging since then, as of September 24, 2019, 805 cases of lung injury from 46 states and one territory had been reported to the CDC.

On March 10, a petition was launched on the White House's website, asking the US government to make public the real reason for the closure of Fort Detrick, and to clarify whether the laboratory is the research unit for the novel coronavirus as well as whether there was a virus leak. The petition also noted that a large number of English news reports about the closure of Fort Detrick were deleted.

Those are questions from not only Americans, but also people across the world. Why has the US refused to provide further explanations concerning the lab? Does the electronic cigarette disease have any connections with COVID-19? Why were reports about the lab deleted? Was the US trying to cover something up?