Two litter pickers in Yorkshire, England, drove a bumpy road home on Monday, not realizing that they had a live World War I era bomb jostling around in their car.

Rachel Wills and Simon Briscombe believed that they had picked up an old gas canister while litter picking at the River Nidd in Knaresborough, and loaded it into their car for later, proper disposal. Unfortunately, proper disposal, in this case, would require a bomb squad, as what they had picked up was a bomb – a live one.

The couple drove half a mile (0.8 kilometers) with the bomb jostling around on the passenger seat, according to BBC News. They only discovered what it really was when they "scraped the gunk" off the device, prompting a quick call to the bomb squad. They photographed the bomb and wrapped it in sandbags, then waited nervously for the professionals to arrive.

Making the wait even more tense, the bomb began "frothing" and "bubbling".

"We've found some really strange things, including a sewing machine from 1898, trolleys, money, shoes, all sorts," Wills told the BBC. "But I can't believe we found what we found and it was live."

"We had it in our car, a live bomb, and we were driving over speed bumps too."

On arrival, the couple was evacuated along with about 30 other nearby families while the Explosive Ordnance Disposal disposed of the bomb.

“We’re still in shock. If Simon had known what it was he wouldn’t have moved it," Wills added. "The police were horrified because he brought it home in the car and there are a lot of speed bumps in Knaresborough. But we didn’t know what it was.”

The bomb was disarmed and removed without issue, despite the bumpy car journey followed by some ominous frothing.

"I just want to put the story right that yes it was explosive, I’m just glad that kids didn’t find it, and as soon as we washed the thick mud off and realised what it could be, we immediately rang the police," Wills, who owns the local Watermill Cafe updated her followers on the cafe's Facebook page.

"We thank our fantastic emergency services for dealing with the matter and making it safe."