“This is actually painful for me to retell. Nine years ago I worked at a school in a small Northern town - let’s just say it’s infamous for huge chemical works nearby. This was no ordinary school, however, but a “special” school for disabled children. And one Tuesday I was tasked with leading a group of kids on a day trip.

The idea was simple: a pleasant barge voyage around the local canals and waterways. Except I was bored out of my head. Tootling along at 4mph, making sure none of the kids fall in, isn’t the windblown thrill ride you’d imagine, and I was almost dozing off.

Suddenly, I spotted some fun. Up ahead, in a housing estate, someone had obviously started some sort of bonfire – and a soup-thick cloud of yellowish smoke was blowing across the canal. In a moment of inspiration, I remembered I’d brought my set of bongos with me. Tying the barge’s rudder so it couldn’t move, I leap up to the front and sat down, cross-legged. And as we drifted into the smog bank, I began to play. . Glancing behind, I saw all the kids were loving it. Nodding, clapping, some had even started dancing. It was brilliant – like something out of Apocalyse Now.

And the excitement continued, right up until the moment the barge emerged from the dense smoke, when we were greeted by six fire engines and four ambulances. Turns out the entire town had been warned to stay indoors, with windows shut, because a chemical firm had suffered a leak – several metric tons of chlorine gas to be precise. And we’d sailed right through it. Dancing. All the kids were rushed to hospital; six were kept in overnight for observation. I was voluntary, so the school couldn’t exactly fire me. But it was made very clear: I wasn’t to come back. Ever.”

Jez, via email