CHICAGO (CBS) — A man fired a gun while in the restroom on a Megabus, and then tried to take control of the bus from the driver late Tuesday night, before another passenger tackled him and held him down until police arrived.

Passengers got more than they bargained for, when the suspect reportedly began harassing the driver as she drove the bus at top speed along the Jane Addams Memorial Tollway, as the bus was making its way to Madison, Wisconsin, and Minneapolis, Minnesota.

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“He was grabbing the bus driver as if he was trying to snatch her out of the seat,” said passenger Kenneth Smith.

That’s when Smith shouted at the suspect, until he went up to the second level of the bus.

What happened next was just as frightening.

“He went in the bathroom and fired off a shot. It was real loud. We didn’t know what it was,” Smith said.

Police were unsure if the suspect fired the gun accidentally or intentionally, but seconds later, he was back again, trying to wrestle control of the bus away from the driver.

“He was grabbing at his hip. I already seen that, and I told him he was getting too close. As he kept coming, that’s when I rushed him. I choked him. He fell to the floor,” said Smith, a 6’2”, 233-pound semi-pro linebacker. “I had to just rough him up. We just wrestled down, and I found out he had a gun, so I took it, gave it to the driver, and that was it,” Smith said.

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Smith and other passengers pinned down the suspect, as the driver pulled over at the Des Plaines tollway oasis, and waited for police to arrive.

The unruly passenger was arrested by Des Plaines police.

Smith, who was on the way to visit his 6-year-old son in Minneapolis, was hailed as a hero by other passengers on the bus.

“The bus could’ve crashed, anything, the way the guy was aggravating the bus driver. So that guy right there is a hero,” Ken Hasley Sr. said.

Megabus officials said the passengers were transferred to a second bus, and continued to their destinations. No passengers were injured. The bus arrived safe in Minneapolis later Wednesday morning.

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The suspect was being held at the Des Plaines Police Department, but Illinois State Police were investigating. Sources said the gunman was not being cooperative, refusing to give detectives his name. No charges had been filed as of late Wednesday morning.