United Airlines is warning employees to prepare for a massive round of layoffs if the travel industry doesn’t pick up.

In a memo sent to employees, the airline announced that 36,000 employees or 45% of its front-line workers in the United States, and more than a third of its overall workforce of 95,000, could be laid off in October.

Flight attendants, customer service, and ticket gate agents would be impacted the most, as reported in USA Today.

The furloughs would reportedly include 15,000 flight attendants, 11,000 customer service and gate agents, 5,500 maintenance workers, and 2,250 pilots. As a condition of the $5 billion in federal payroll aid United received this past spring, the company cannot layoff workers before Oct. 1.

A recovering airline industry looks grim as ticket sales remain low. Meanwhile, the number of coronavirus cases are increasing nationwide, which poses a threat to a sector hoping to recover amid the global health crisis.

Air travel dipped more than 95% from March 1 until mid-April. Fourth of July weekend recorded the highest number of U.S. air travelers since mid-March but the total amount of travelers was still down about 70% from a year ago.

United executives said during a briefing with reporters that they hope the final tally, which will be known in mid- to late August, will be less than 36,000 as more employees accept voluntary exit programs. 

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The airline has extended the application window for its voluntary separation program to July 15 to encourage more employees to sign up.

“After months of aggressive cost-cutting and proactive capital-raising, today we updated employees about a topic we’ve always dreaded and the action that was always a last resort in the context of this COVID-19 pandemic: involuntary furloughs,” the statement began. “The reality is that United simply cannot continue at our current payroll level past October 1 in an environment where travel demand is so depressed.”