The Texas-based company filed for bankruptcy protection on Nov. 29 after posting $11 billion in losses since 2001. Corporate executives have said the company plans to lay off about 13,000 employees companywide, including thousands of mechanics, flight attendants, pilots and management staff as it goes through reorganization. American hasn't said which jobs in Tulsa would be targeted or when layoffs might happen.

"These skilled workers are military veterans, mothers, fathers and heads of households," said Rick Mullings, an organizer for the union. "They pay taxes, support local charities … They spend their wages throughout our communities. If they lose their jobs, the impact will be felt throughout northeastern Oklahoma."

Andrea Huguely, a spokeswoman for American Airlines, said the company is "committed to preserving thousands of quality jobs in Tulsa."

"We realize change is difficult, but it's necessary for American to become a successful company and continue to employ thousands of people in Oklahoma," she said. "Our roots here are deep — dating back nearly six decades."

Labor talks are ongoing between company representatives and union officials.

"There's more fear and uncertainty than there is optimism," said Gary Elias, a 25-year employee.

The maintenance hub's economic impact on the Tulsa region is enormous. City experts estimated that if all 2,100 jobs were eliminated, the city would lose $300 million annually, including about $5 million in county and sales tax revenue.

There are hundreds of mechanics and technicians on the list of America workers who could be targeted. Distributed by the corporate office Wednesday, the list includes 4,000 mechanics and work groups, 4,200 fleet service and other Transport Workers Union workers, along with 2,300 flight attendants, 1,400 management and support staff, and 400 pilots.

American serves around 240,000 passengers per day.