A normal Metro ride on the Green Line Wednesday night turned frightening for dozens of people who believed they heard gunshots on a train headed to Branch Avenue. Panicked, a crowd of people on the train burst into a neighboring car, yelling about a shooter and cowering behind seats as the train pulled into the Waterfront station, according to a witness at the scene and a Reddit conversation about the incident.

“I just ran through a metro train with 50 or so other people that were yelling ‘shooter’ as the train pulled into the Waterfront station. Scariest thing I’ve ever experienced,” the Reddit post begins. “I was in the fifth car I think reading a book on my way home when ten or so people burst in through the car door next to me. I joined them and ran to the back of the train. Everyone was shoving everyone else and some where [sic] hiding behind seats. After waiting around for five minutes with others at the back end of the station, I made my way out. As I came up out of the station, five cop cars rolled up emergent and about ten cops ran in with guns drawn, assault rifles and all.”

As it turns out, there were no shots fired.

According to a witness on the train car where the panic began, an agitated man entered the train at L’Enfant Station holding a large tool. When the train started moving, the man yelled and banged it on the ground of the Metro car repeatedly. People on the other end of the train car couldn’t see the source of the noise and began rushing into a neighboring train car in a panic.

“I could see what was going on because he’s right in front of me,” recounts the witness, whose Reddit username is MrTacoMan (he declined to be identified by name so it would not be linked back to the account). “The people in the back of the car just see people moving quickly away from this person, and people start yelling and freaking out and clearing out of the back of the car.”

This is the second time in recent months that a crowd has fled Metro out of fear of an active shooter. In January, chaos ensued after fireworks went off on a train that was pulling up to Gallery Place station. The station doors were open when the firework ignited, and people in the station believed they heard gunshots. Riders left possessions on the platform and fled, and some dove into a train that was just pulling away from the platform, the Washington Post reported at the time.

“There is no higher priority than the safety and security of Metro customers and employees. Training and full-scale response drills are conducted for employees, Metro Transit Police, and law enforcement agencies throughout the region,” says Metro spokesperson Dan Stessel. “In fact, Metro has been conducting active shooter exercises for more than a decade.” The most recent drill took place on September 9.

And at the D.C. Pride Parade in June, hundreds of people ran away in a panic after reports of a potential active shooter. It turned out that a man threatened another person with a BB gun. The parade ended early as a result of the incident, and left a number of attendees shaken.

Metro Transit Police said that officers on Wednesday responded to a “report of a loud noise” on the Green Line train. “No weapons were found, and the noise was determined to be caused by an individual dropping a heavy tool. The train was released after being held for about 3 minutes.”

But it was enough to create a panic.

“The scariest part was the minute when the train was stopped at the station and the doors hadn’t opened yet. Everyone in the back was yelling for the doors to be opened,” a third Reddit user wrote.

The witness that DCist spoke to said that about 80 percent of his car cleared out in the panic. As he exited the station, he saw police officers coming down the stairs with rifles. “I yelled at him ‘No no no he has a wrench, it’s a wrench. There’s no gun, it’s a wrench.'”