Thousands of emergency medical technicians and paramedics are on the front lines of disasters, accidents, and potentially deadly circumstances every day. Caleb Henry was one of them until he quit his job in 2018 because of the constant barrage of trauma he witnessed on the job in California.

“There are calls that I do not forget,” Henry told HuffPost. “There are calls that I still think about.”

The 21-year-old former EMT has been diagnosed with depression, anxiety and PTSD. After a couple of years of long workdays and nightmarish memories from on-the-job horrors with zero in-house health resources, Henry said the work took a toll on his mental health.

“A 14-year-old girl was walking on the tracks, listening to music and was hit by the train,” Henry said, recalling one assignment that still haunts him. “She was losing a lot of blood. We did all we could. She died en route to the hospital.”

Long afterward, he said, he found himself “replaying the scene in my mind, obsessively.”

“I can’t go near a train track,” he said. “It really triggers me.”

In this profession, mental illness is common. EMTs and paramedics experience higher rates of PTSD, major depression, substance abuse and suicide than the general population, according to scientific studies in the U.S. and England. This high-stress career path also holds increased risks of physical health problems and complications.

First responders can run on little sleep during long shifts, faced with graphic scenes and little time “to stop and breathe,” according to Henry. The pressure of life and death hangs over every action.

“As much as a therapist could tell you that you’re not responsible for someone’s death ... that is your patient,” Henry said. “You’re making the decisions. They’re your patients. Was it something that I did? Did I make a wrong decision? Did we take too long? There is that responsibility.”

Despite the physical and mental toll of the job, paramedics and EMTs don’t always earn as much as other first responders. Many paramedics juggle multiple jobs because of low pay ― an average of $16.50 an hour in 2018, according to the Bureau of Labor Statistics. That’s 40% less than what the average American earned, Money magazine reported.

In New York City, for example, they lag behind firefighters in pay and benefits, according to a New York Times editorial published in September.

As that suggests, the first responder pecking order often leaves EMTs and paramedics overshadowed by police officers and firefighters. In July, President Donald Trump allocated $7.5 million annually for five years for mental health services for police officers, but nothing for paramedics, EMTs or firefighters.