A broad and bipartisan group of senators is coalescing around legislation to create a high-level independent commission, modeled after the one that examined the Sept. 11 attacks, with broad powers to investigate the origins of the coronavirus pandemic and the response across the Trump and Biden administrations.

Under a plan proposed by the top Democrat and Republican on the Senate Health Committee — Senators Patty Murray of Washington and Richard M. Burr of North Carolina — a 12-member panel would have subpoena power to “get a full accounting of what went wrong during this pandemic,” Ms. Murray said in an interview, and make recommendations for the future…

“I’m all for it,” declared Senator Roger Marshall, Republican of Kansas, a medical doctor who is working with Senator Kirsten Gillibrand, Democrat of New York, and others on a similar bill. “As a doctor, if a patient dies and we don’t know why, we do an autopsy. In the military, when we have a major event we go back and figure out what we did right and what we did wrong.”