The nightmares have been relentless.

Joel Loomis remembers seeing police cars racing toward the store where he works. He remembers hearing reports of an active shooter. And mostly, he remembers the image he saw on YouTube that still haunts him: his 25-year-old manager, motionless, near the self-checkout, where he’d said hello to her the day before.

In the six weeks since a gunman killed 10 people — including his manager and two colleagues — at the King Soopers market in Boulder, Loomis has come to avoid crowds and public places. He is sad, angry and anxious, and following months of working the front lines of pandemic, worn out.

“A lot of people are quitting, and others are still too shaken up to talk about what happened,” the 21-year-old cashier said. “Wherever I go now, I’m looking at people, thinking, ‘Does he have an assault rifle? Was that a gunshot? How do I escape?’ ”

The Boulder attack and other deadly grocery store shootings, including one last month in Long Island, underscore a new layer of vulnerability for millions of grocery workers, many already overwhelmed after taking on bigger workloads, longer hours and heightened health risks in the year-plus of the pandemic.

The prolonged stress, public health experts say, can lead to depression, anxiety, high blood pressure, heart disease and other conditions. Now they’re dealing with one more stressor, said Bethany Brand, a psychology professor at Towson University in Maryland who specializes in trauma.

“Statistically the odds of any one grocery worker being killed at work are extremely small, but that is not how our brains work,” she said. “The impact of these events is real with heightened levels of stress and anxiety for many employees.”

Even workers not directly affected by the shootings say they are struggling to sleep and are fearful of going to work, as they confront an ever-present threat of gun violence in the workplace. On April 20, less than a month after the Boulder shootings, a gunman opened fire in a Stop & Shop in Long Island, killing one manager and injuring two employees.

“It’s one thing hearing about a shooting, but hearing about it happening in a place like where you work just makes it even more real,” said Trish Gross, 28, a cake decorator at a grocery store in Long Beach, Calif. “Now I think about it every single day I’m at work: What I would do, where I could hide. It’s something that’s on my mind constantly.”

She has trouble winding down for bed and often gets as little as four hours of sleep before waking at 3:30 a.m. for her morning shift. The past year, she says, has been a string of stresses: A disease that’s killed hundreds of grocery workers and infected thousands; verbal and physical altercations from customers who don’t want to adhere to mask requirements; and now, store shootings.

Loomis hasn’t returned to work and says he’s unsure he ever will. A junior at the University of Colorado at Boulder whose two roommates also worked at King Soopers, he says he feels brushed aside by store management and the parent company, Kroger. Like many of his colleagues, he’s applied for workers’ compensation but says his claim was denied because he wasn’t clocked in at the time of the shooting.

Kristal Howard, a spokeswoman for Kroger, which owns the King Soopers in Boulder, said the company is “focused on helping our associates, customers and our community as they continue to grieve and heal.”

She also said the company’s hardship fund has given $500 grants to workers in Boulder and is offering free virtual counseling sessions to all employees.

Stop & Shop, which is owned by Ahold Delhaize USA, is providing employees with grief counseling, as well as financial assistance for funeral and hospital expenses following the shooting at a Long Island store, said president Gordon Reid.

Still, Loomis says, he’s dealing with symptoms of trauma and isn’t sure where to turn for long-term help. As a part-time worker, he doesn’t qualify for the company health insurance and says he can’t afford to pay for a therapist out of pocket. The ones he was referred to by Kroger’s workers’ compensation insurance company, he said, are not accepting new patients. (Howard disputed this claim and said counseling resources continue to be available for employees.)

“I keep wondering, ‘Can I just move on?’ ” he said. “I want to tell myself, ‘That was just a freak accident, you are safe.’ But I don’t feel safe.”

Chelsea Krasawski was breading chicken tenders at the Boulder store when she heard the first gunshots.

The deli worker ran into a supply closet, then out a side exit to the safety of her car. She waited there to see if any colleagues might follow her out before realizing shoppers were still driving up to the store, unaware of what was unfolding inside. She parked her Honda CR-V in front of a parking lot entrance and stood outside, trying to redirect traffic. But conveying the gravity of the situation to unsuspecting shoppers was nearly impossible, she said. The store was eerily quiet; there were no screams or sounds of chaos. She remembers one woman in her 80s who insisted on going inside to buy groceries.

“I walked over to her window and told her, ‘There’s an active shooter inside. Please turn around, you have to leave right now,’ ” Krasawski, 27, recalled. “But it didn’t seem to sink in. It’s one of those things where it’s like, ‘No, that can’t be real, that can’t be happening.’ ”

Krasawski said she stayed for nearly 45 minutes, watching as an armored police vehicle broke through the store’s glass windows. She heard a voice on a loud speaker telling the gunman to surrender. She didn’t leave until a police officer told her she had to, then she sped home, making what’s normally a 25-minute drive in less than 10. Her 4-year-old and husband were napping, so she ran into the bathroom, slammed the door shut and broke down.

Even now, all these weeks later, she can’t shake the feeling that she’s in danger. The thought of walking back into any grocery store puts her in a panic, she said. Sometimes just seeing the King Soopers logo makes her anxious.

“Now I’m thinking about things that never crossed my mind before: How many exits are in a grocery store? Did my son’s teacher remember to lock the door to their class?” Krasawski said.

She’s filed for workers’ compensation and found a therapist, though her first appointment is still weeks away. The trauma of the shooting, coupled with financial worries, makes her feel as though she’s constantly on guard. Krasawski and her husband both lost their jobs at a solar company in Tennessee early in the pandemic. They moved to Colorado in August, and Krasawski took a part-time job at King Soopers to make ends meet, joining the hundreds of thousands of grocery workers hired in the past year to keep up with swelling demand.

On the afternoon of the shooting, she had been wrapping up an eight-hour shift when the gunman entered from the other side of the store and opened fire. The next day, she learned that Denny Stong was among the victims. The 20-year-old worked the overnight shift and had been at the deli counter just minutes before the massacre, buying chicken tenders and chatting with her and a colleague, she said. He hadn’t been working that day but had stopped by to pick up lunch and say hello to his mother, who worked at the front of the store.

“To see Denny’s name on that list was absolutely heartbreaking,” she said. “To know that his mother had to walk out of the store without him — as a mom, that wrecked me. That hit me harder than anything else has.”

Ten people were killed, including a police officer and five customers, before the alleged gunman was arrested following a shootout with police. Authorities have not announced a motive or said whether the 21-year-old — who faces 43 charges, including 32 counts of attempted murder — had any connections to the store. It was the country’s deadliest mass shooting since 23 people were gunned down at an El Paso Walmart in 2019.

Gun violence has become an ever-growing threat over the last half-century, starting with the 1966 shooting by a student at the University of Texas at Austin that killed 17. Since then, 1,312 people have been killed in mass shootings nationwide, according to a Washington Post analysis. Those shootings have occurred just about everywhere: stores, restaurants, hospitals, movie theaters, even nursing homes.

Though retailers including Walmart, Target and Walgreens have expanded mental health resources during the pandemic by offering access to virtual therapy, as well as meditation and sleep apps, workers groups and unions say they aren’t doing enough to address systemic issues such as low pay, food insecurity and uneven access to health insurance, or the collective and sustained trauma many grocery workers have faced in the last year. The industry’s low wages — median pay for grocery employees is about $13 an hour — and high turnover rate add additional layers of vulnerability, they said.

Marc Perrone, president of the United Food and Commercial Workers International Union, which represents 900,000 grocery employees, said the union has provided grief counselors to workers at the two stores where there have been recent shootings, and is also urging companies to add more security guards.

And while workplaces around the country have added active shooter drills and discussed lockdown scenarios with employees, mental health experts say they have been slower to address the trauma that such events can leave behind. Some workers may be scared to return to work or find that violent events in the news can be re-traumatizing, said Amy Nitza, director of the Institute for Disaster Mental Health at the State University of New York at New Paltz.

At the very least, she and others said, employers should communicate clearly and give workers more say over their day-to-day shifts and schedules. Frequent breaks throughout the day are also important, particularly for those who work directly with the public.

“The return to work obviously has the potential to be triggering,” Nitza said. “Sometimes with acute traumatic events, it is the aftermath that is as stressful and difficult to recover from [as] the actual event.”

King Soopers held a vigil at a football stadium a few days after the March 22 shooting, where Kroger executives spoke about the importance of supporting their employees. A town hall at the local university basketball arena followed a few days after. Employees were given $100 gift cards to Door Dash and could get coronavirus vaccines on the spot. The store also set up an employee resource center above a Chase bank in the same shopping center as the King Soopers, complete with counselors, therapy dogs, massage therapists and human resources employees.

The store will remain closed for renovations, but Kroger gave each worker $500 and will continue to pay employees for the hours they would’ve worked through mid-June.

But Loomis says it isn’t enough for a grocery chain that last year brought in $2.6 billion in profits.

“People have families they need to support.” he said. “They were at work and saw their friends die. Five-hundred dollars is supposed to make it all better? It’s a slap in the face.”

He says he pressed human resources on the issue and suggested the company give more financial support to affected employees but was told the company was already spending $3 million to renovate the store after the shooting. The company representative, he said, told him he was being difficult and encouraged him to quit.

Howard, the Kroger spokeswoman, declined to comment on individual conversations. She noted that the company is encouraging managers to “lead with greater awareness, compassion and empathy.”

Thirty minutes away, at another King Soopers in Colorado, pharmacy technician Marsha Esparza-Barnabe says she’s become terrified of dying at work. She looks at customers differently now, trying to size up whether they’re hiding a gun under their jackets or in a back pocket. She is sleeping less, and she’s more irritable with her family.

“This past month has been really tough, especially on top of the year we’ve had,” the 58-year-old said. “And it’s not something you can just leave outside your house. You bring it in with you, so it affects everyone.”

Esparza-Barnabe, who has diabetes and asthma, says she’s lived much of the past year in fear of contracting the coronavirus and passing it on to her household, which includes her son, daughter-in-law, grandson and his girlfriend. She lost her job early in the pandemic, as did her son and daughter-in-law, adding to the stress.

Life feels more isolated, too. She doesn’t chat with co-workers the way she used to, and she can’t meet up with friends for dinner. It’s all taken a toll.

“It has been one stress on top of another,” she said. “The stress of not having a job. The stress of getting sick. The stress of getting shot.”