The latest findings of STR, a lodging research company, were equally stunning: In the week that ended April 11, hotel occupancy in the United States was down 70 percent from the same week in 2019, to 21 percent, and hotels’ revenue per available room, the major barometer of profitability, was down 84 percent to $15.61.

These declines, said Jan Freitag, senior vice president of STR, are the “steepest” ever measured by the firm, whose data goes back to 1987.

About a third of the association’s corporate travel managers said they expected business travel to resume in the next two months, while about one-fifth said in three months. Another 16 percent didn’t even hazard a guess.

A poll this month of 106 corporate travel managers who work for BCD clients found similar pessimism about any quick return, with a little over 40 percent saying they expected business travel to return to former levels this year. Another 10 percent predicted that it would not fully return until at least 2022, while 3 percent said it would never return.

“Business travel won’t come back before we hear from public health officials that it’s safe to travel,” Mr. Harteveldt said. “Once we hit the point where the virus is contained and, hopefully, treatment is available, I believe business travel will start to resume, assuming the economy hasn’t gone into a deep recession or, worse, a depression.”