Originally Published: 02 MAY 22 15:05 ET

By Sara Ashley O'Brien, CNN Business

(CNN) -- The grassroots labor union that made history last month when it formed the first union at an Amazon warehouse in the United States has lost a union election at a much smaller facility just across the street.

The election, held last week at the Staten Island sorting facility known as LDJ5 and the votes of which were counted Monday, was the second to be organized by the Amazon Labor Union (ALU), a newly established union, started by a local group of Amazon warehouse workers and led by a fired employee.

A public tally of the vote, held Monday at the National Labor Relation Board's Brooklyn office and broadcast over Zoom, heavily favored not unionizing. There were 618 votes against unionizing and 380 in favor. Out of approximately 1,633 eligible voters, 998 votes were counted. There were no challenged ballots. Two ballots were voided.

The LDJ5 election drew significant attention from prominent labor leaders, including Sen. Bernie Sanders and Rep. Alexandria Ocasio-Cortez who rallied with Amazon workers on Staten Island a day before the election started.

The ALU's unlikely success in its first election at Amazon's JFK8 warehouse, which employs more than 8,000 workers and is also located on Staten Island, potentially exposed broader implications for Amazon's sprawling network of facilities.

ALU's organizing efforts grew out of tensions between Amazon and Staten Island workers over the company's pandemic response along with existing frustrations about working conditions. Amazon's workplace has been under scrutiny for its high turnover rates and on-the-job injuries in recent years. Christian Smalls, who was fired by Amazon at the start of the pandemic and is now ALU's president, called the initial win "a catalyst for a revolution with Amazon workers, just like the Starbucks unionizing effort" in an interview with CNN last month. "We want to have the same domino effect."

Amazon has repeatedly said in statements that its "employees have always had the choice of whether or not to join a union," while spending millions on consultants to combat unions last year alone and running an anti-union campaign inside the facilities. Amazon said it was "disappointed" with the JFK8 results and laid out a number of objections to the previous Staten Island union vote as it called for a do-over; an NLRB hearing on the matter is scheduled for later this month.

"All the issues are the same. Of course there are differences between the buildings, but we need the union at JFK8. We need the union at LDJ5. We need the union at all Amazon warehouses all across the world," said ALU's treasurer and LDJ5 employee, Madeline Wesley, at a union rally ahead of the LDJ5 election. "This is just the beginning."