Food Fight: Assaults on Restaurant Workers on the Rise Across America, Investigation Finds

It's a disturbing trend that's on the uptick.

Some fast food restaurants look more like a battleground than a place to grab a quick bite.

Startling incidents of violence are occurring around the country. In Maryland, two Subway customers started fighting inside the shop before crashing through the store window.

Read: Groups of Cyclists Causing Congestion and Absolute Mayhem in the Streets, Investigation Finds

At a Minneapolis McDonald's, an out-of-control customer got upset about the service, grabbed the employee by the tie and pulled him out the drive-thru window.

These are not isolated incidents. Assaults on fast food workers have doubled in five years, according the U.S. Bureau of Labor Statistics.

When Amanda Gaveley pulled up to a McDonalds drive-thru in Des Moines, Iowa, in June, she saw a customer attack a manager.

“I was shocked, I was like, 'Oh my gosh,’” she told Inside Edition. “I said, ‘I need to record this to show how crazy people get at fast foods.’”

Amanda said the customer was upset because she ordered a McChicken sandwich and they were not ready.

When the angry customer was handed her the sandwich, she promptly threw it back. Then she hopped on the counter and hit the manager.

Valerie Shepherd, 21, was charged with assault. She spoke to Inside Edition’s Chief Investigative Correspondent Lisa Guerrero as long as on the condition that her face would not be shown on camera during the interview.

“How do you get to that point over a chicken sandwich? Guerrero asked.

Shepherd responded: “Just the insults, when people are insulting you, it’s hard not to respond back to that.”

“What about the point where you actually throw the chicken sandwich back at the manager's face?” Guerrero followed up.

“I did not throw it at her. I just threw it back because I didn't want it at that point,” Shepherd said. “I was so angry, I didn't care about the food anymore.”

Guerrero went on patrol with Sgt. Eric Rogers of the Los Angeles Police Department.

He says there has been violence at some fast food spots because of “a combination of things.”

“I think first and foremost, just the hours they keep,” he said. “Particularly the ones that stay open 24 hours.”

Read: What Happens to an Unattended Bag With Money Inside? Investigation Puts Honesty to the Test

He also said late night drinking plays a role in the violence. Cops say there are some special tactics that have helped reduce the violence, like at a local Jack in the Box.

“For the first three months of 2017, we had 44 calls at that establishment,” Rogers said.

When Jack in the Box agreed to close the indoor dining area after midnight during the week and only keep the drive-thru open, calls for police service dropped to only three in the next three months.

“It's a constant battle out here,” Rogers said.

Watch: Are Mexican Resorts Serving Up Tainted Booze?