Maria Torres followed eight sprinting co-workers into the kitchen’s walk-in fridge, screaming “Gun!” They locked the door against an armed intruder.

“He was threatening everyone with a gun,” the 58-year-old McDonald’s cook said, recalling that morning last December in the Princeton Park section of Chicago. “He came in very erratic. We couldn’t understand what he was saying.”

After spotting the drawn firearm, Torres knew what was up: “He was trying to rob us.”

Torres is one of many fast-food workers across the US punching in at all hours for low pay and braving threats dished out by knife- and gun-toting robbers, drug-addled marauders, drive-by assassins, perverts, unruly patrons and loiterers baiting for a fight.

“The industry is well aware of the proclivity to this problem and they’re not addressing it,” said JR Roberts, a workplace security specialist and court expert witness.

The Bureau of Labor Statistics (BLS) monitors mortality rates at full-service, sitdown or limited-service restaurants, which includes fast-food restaurants, delis and pizza parlors.

There were 14 homicides at limited-service stores in 2014, 23 in 2016 and 15 in 2017. BLS stats show there were 16 homicides in 2014 at full-service restaurants and 21 by 2017.

The stats reflect only employees killed in violent incidents. Bystander or perpetrator homicides are not counted. Nor are threats of violence against restaurant workers.

One of the central grievances for workers such as Torres, who earned $12 an hour until she was bumped to $15 after the state updated its law, is pay.

“[If] they don’t even give us enough money for work, they’re not going to give us safety,” she said.

The demand for better wages is spreading. A fast-food worker revolution took flight back in November 2012, when some intrepid New York City staffers walked out in protest. The Fight for $15 movement formed.

Already, 22 million low-wage workers have won $68bn in annual raises. Minimum wage plans working up to $15 an hour have been approved in several states including New York, California and Massachusetts and in the District of Columbia.

Last week, US House members voted to pass the Raise the Wage Act bill, which would hike the hourly wage to $15 from its current $7.25 minimum over six years. It now heads to the Senate. The threats that such workers face have become a central pillar in the fight.

Some turn fatal, as was the case with the 28-year-old McDonald’s manager Adam Garcia, who in 2016 was fatally stabbed in a Bronx parking lot by a homeless man, hours after he had been shown the door.

In other cases, danger is averted. Security guards at a Wendy’s in the Franklin Heights section of Milwaukee have given Audrey Taylor confidence in her safety. While the 56-year-old admits to witnessing fights, the store has “cameras everywhere” and foreboding guards, described as “big-boned” and “tough”, carrying Tasers and firearms.

But guards cannot solve every situation. At an Oakland McDonald’s, one security guard tried pepper-spraying a customer.

“I started coughing uncontrollably,” said cashier John D’Amanda. “Everybody backed away and went to the farthest corner and ultimately left the restaurant.”

The 59-year-old recalled how in January, a teenager refused requests to park her motorized scooter outside. She then “tackled the manager from behind the [counter] gate and threw her to the ground”, he said.

“She was so strong,” he said, remembering how he helped pull the teen off the manager as she gripped a wad of her hair. The teen then flung the french fry basket at D’Amanda and his manager. After the teen fled, her pals returned – because the teen “wanted a refund”.

D’Amanda confirmed the incident was reported to the police.

‘Numbers versus the gut’

According to a recent report by the National Employment Law Project, some 721 incidents of violence at McDonald’s restaurants over a three-year period have been reported by police in 48 states and covered by the press. But the study notes that threats and abuse generally go “unreported to the authorities” putting “both workers and customers at risk”.

For McDonald’s alone, with its 14,000 stores, the report cites a torrent of workplace violence, often ignited by “belligerent customers”. In one case, a manager was shot in the neck over an argument about a frappé iced coffee. All “are indicative of a pattern of violence that occurs in their workplaces on a routine basis”, the report says.

The company argues robust safeguards are in place.

“We believe every person working in McDonald’s restaurants deserves to do so in a safe and respectful environment and, along with our franchisees, have invested in programs that promote safe environments for customers and crew members,” the company said in a statement, adding that it follows strict anti-violence policies.

“This includes clear policies that strictly prohibit violence, threats of violence and other conduct that jeopardizes or harms the safety of employees and others in the workplace and during work-related activities. Throughout the rest of the year in our corporate-owned US restaurants, we will roll out national training initiatives that we’ve developed, focused on employees’ safety in the workplace to further ensure that anyone who comes into a McDonald’s feels safe, secure and respected.”

Representatives from Wendy’s, Burger King and KFC’s parent company Yum! Brands did not respond to repeated requests for comment.

The National Restaurant Association, a trade organization that represents more than 500,000 restaurants and a diverse workforce, said it is not complacent.

“Violence of any sort should never be tolerated in the workplace,” said a spokeswoman, saying restaurant owners and operators are helped to “maintain a safe and inviting environment for employees and guests”.

The spokeswoman also pointed to safety “training” that is “offered to all of its members”, though she also said “the National Restaurant Association does not speak on behalf of individual restaurants nor monitor where and how the trainings are implemented.”

Instead, it is up to the companies themselves to set their own “safety policies and procedures”.

Kevin Trimble, president and founder of Loss Prevention Solutions and an industry expert with almost 30 years experience and formerly the US director of security for McDonald’s, defended the company’s efforts to protect its workers and stressed that paying for safety was never an issue.

“There was never anybody saying, ‘We can’t afford this,’” he said. “We didn’t want to compromise the wellbeing of the customer or the employee. It cheapens the effort.”

Trimble was directly involved in the design and implementation of a risk assessment tool which “evaluated and measured multiple data points” to make forecasts based on previous incidents as to where crimes may occur.

“There was a significant amount of improvement,” he said. “We were able to manage risk by numbers versus the gut.”

Other crime curbing measures involved “implementing public view monitors” where customers (and would-be crooks) could see themselves on CCTV. If necessary, a restaurant’s hours were adjusted to close earlier if concerns were identified.

After the armed robbery in Chicago, Maria Torres noticed that franchise management made adjustments. Bars were bolted to the drive-thru window and extra guards were hired. But the worker, who has served McDonald’s for over a decade, claims the guards’ hours were then scaled back.

Records provided by the Chicago police department show Torres’s McDonald’s, by US Route 12, was hit with 24 crimes that drew police responses in 2017. There were two robberies, six battery cases and four assaults.

In 2018 there were 23 incidents, including a kidnapping, a criminal sexual assault, a weapons violation, another pair of robberies and five assaults.

By the end of February of this year there had been eight cases, including two assaults and three batteries.

One fall evening in 2017, Maria Paez left her McDonald’s on Fillmore Street in San Francisco. She walked into a spray of bullets unleashed by a drive-by shooter, aiming “at people on the sidewalk”.

“I hid underneath a car parked on the street and waited until it was over,” recalled the 53-year-old cook, who makes $14 an hour. “I thought it was a machine gun because of the number of bullets.”

After the fusillade, Paez tried to press on at work but the memory remained.

“We would hear loud sounds and duck because we don’t know if there was [more] gunfire,” she said.