A picket line went up at 6 a.m. in front of the Verizon facility at 9th and Race streets in the Chinatown section of Philadelphia.
Workers began gathering at about 5:30 a.m. outside the facility. By 6:30 a.m., the group of picketers had grown to several dozen.
PHOTOS: The 2016 Verizon strike
Police were on hand to ensure the safety of the workers and passersby, and to direct traffic in case the growing crowd of striking workers began to spill out onto Race Street.
Edward Mooney of the Communications Workers of America was among several workers saying that while the strike is in part about wages and benefits, the big issue is keeping jobs from going overseas.
"What the company wants to do is subcontract the work to out-of-state contractors or, in the call center environment, sometimes out of state or out of the country," said Mooney.
Recent retiree Lisa Ann Faber, channeling her inner Wonder Woman, joined the picket line. She tells us for her it's a battle line for middle-class existence.
"To be able to raise your family above the poverty level," said Faber.
Karen Lane, of IBEW Local 827 put it this way: "Here's 39,000 people that are saying 'enough is enough,'" she told Action News. "So I'm hoping the public will stand up and say, 'Okay I've got 39,000 people behind me, I'm ready to say that's enough.' We can't keep sending these good, middle-class, paying jobs overseas."
In a statement, Verizon responded:
"Saying that we're looking to send jobs overseas or to contractors is absolute nonsense and the union needs to start telling the truth."
RAW VIDEO: Verizon workers go on strike
As an international company, Verizon says they have overseas offices, but more than 80 percent of the union workers, all those hired before 2003, cannot be laid off.
"True," says the union, but what about those hired after 2003?
"Everybody new we get now does not have job security, and they would like to contract out jobs out, but we want to keep them good, middle-class, American jobs," said Randy Rahn, CWA
On the bargaining table, Verizon has offered wage increases, continued retirement benefits, 401Ks with company match and healthcare.
But many longtime employees want it in writing and are concerned about their future.
The striking Verizon workers, members of two unions - the Communications Workers of America and the International Brotherhood of Electrical Workers - represent installers, customer service employees, repairmen and other service workers in Connecticut, Delaware, New York, New Jersey, Massachusetts, Pennsylvania, Rhode Island, Maryland, Virginia and Washington, D.C., for Verizon's wireline business, which provides fixed-line phone services and FiOS Internet service.
The workers' latest contract expired in August and so far, the unions and management say negotiations have been unsuccessful.
The unions have said Verizon wants to freeze pensions, make layoffs easier and rely more on contract workers. The telecom giant has said there are health care issues that need to be addressed for retirees and current workers because medical costs have grown and the company also wants "greater flexibility" to manage its workers.
Verizon also is pushing to eliminate a rule that would prevent employees from working away from home for extended periods of time. In a television ad, the unions said the company was trying to "force employees to accept a contract sending their jobs to other parts of the country and even oversees."
"The main issues are job security and that they want to move workers miles and miles away," said Isaac Collazo, a Verizon employee who has worked replacing underground cables in New York City for nearly 19 years.
"We have a clause currently that they can't just lay anyone off willy nilly and they want to get rid of that," said Collazo, a single father of three children. "I feel if the company had the opportunity, they would just lay people off."
Verizon said Tuesday that it has worked for more than a year to prepare for the possibility of a strike and has trained thousands of non-union workers to fill in for the striking workers. Employees from other departments across the U.S. also will be sent to replace the striking workers, the company said. In August 2011, about 45,000 Verizon workers went on strike for about two weeks.
"Let's make it clear, we are ready for a strike," Bob Mudge, president of Verizon's wireline network operations said.
The replacement workers, Mudge said, "know our first priority is maintaining services for our customers and they have taken on this challenge with pride."
Verizon Communications Inc., which has a total workforce of more than 177,000 employees, said in a statement Tuesday that the company was contacted by federal mediators and is willing to sit down and continue negotiation talks, if the unions agree to hold off on their strike. A spokeswoman for CWA said the union did not authorize the mediators to offer to extend the strike date.
The Associated Press contributed to this report.