Workers at nine Amazon facilities across the U.S. are now on strike, as the International Brotherhood of Teamsters continues its attempt to push the company to the table to negotiate on a collective bargaining deal.

The first strikes began on December 19, starting with Amazon's DBK4 warehouse in New York City, DGT8 in Atlanta, Southern California's DFX4, DAX5, and DAX8, DCK6 in San Francisco, and DIL7 in Illinois. Over the next two days, they were joined by workers at the KSBD air hub in San Bernardino and Staten Island's JFK8 warehouse. 

“These workers have the courage to face down a giant and the conviction to demand what they’ve rightfully earned," Teamsters president Sean O'Brien said. "No matter how hard Amazon tries to hold them down, our members’ spirits are strong and will never be broken,”

In a December 20 statement to CNN, the company said that it doesn't expect the strikes to delay deliveries ahead of the Christmas holiday, and that as a policy, they "plan for contingencies to minimize potential operational impact or costs."

The Teamsters say that they represent more than 10,000 Amazon workers combined across 10 U.S. warehouses and delivery stations. The union has been calling on the company to bargain with workers on improvements to pay and job safety for weeks, initially setting a December 15 deadline to begin those negotiations. When that day came and went, dominoes began to fall, as workers at facility after facility joined picket lines. Amazon has repeatedly insisted that the Teamsters don't represent their workers, and has refused to recognize JFK8's union, years after the facility became the company's first in the U.S. to successfully organize.