I was desperately trying to snap photos from the sidelines of the Columbia County Fair Demolition Derby when a giant “OOoohh!” rippled across the crowd, a contradictory noise of concern and excitement delivered en masse by thousands of rapt spectators.

“What happened?”

My girlfriend pointed to the other side of the rectangular track. One of the cars had broadsided a sedan in reverse and flipped it on its roof, then rolled up the sedan’s undercarriage so it came to a rest on top of the other car, its brake lights pointing to the dimming sky.

The announcer yelled for the rest of the cars to stop, and the referees, looking like recently escaped convicts in their orange jumpsuits, vaulted over the concrete barrier enclosing the derby and rushed to the cars. The driver of the sedan emerged, unscathed, raising his fists to the sky with a roar of approval from the crowd. The second driver wiggled out, and massive yellow loaders disentangled the crumpled vehicles from their inverted embrace.

The two drivers then climbed back into their cars, and the demolition derby was back on.

It was the second qualifying heat in the 6-cylinder demo competition, where about 20 mid-sized cars smashed into each other until all but four were disabled. These were the winners, and they moved onto the next round.

The track is saturated before the derby to ensure no cars are doing 50 MPH when they make contact with their competitors, and safety is addressed as seriously as possible for an event essentially consisting of adult bumper cars.

Two of RIch Bauer and Noah Casivant’s six cars for Thursday Night’s Demolition Derby at the Columbia County Fair.

I spoke with two competitors the afternoon before the Mad Max-style deathrace as they finished working on the six cars they were entering in Thursday’s competition. Rich Bauer, 40, had been competing in the Columbia County Fair Demolition Derby “for about 15 years,” while his nephew, Noah Casivant, 19, was entering his first derby.

The six cars were splattered with technicolor graffiti and parked at random angles across a wide lawn in Greenport four hours before the event. One vehicle had “Not An Uber” sprayed across it, while another had “Cheddar Bob” festooned across the trunk — the nickname Rich had given Noah, derived from the Eminem film “8 Mile.” A third car read “R.I.P. Pistol,” a call-out to a friend of Rich’s who’d passed.

The two had only one trailer, so they would be whizzing cars up to Chatham one at a time in the hours before the derby. Because of the wrath visited upon the vehicles, a different car was needed for each heat, so Rich and Noah had a second car to hop into if they got through the qualifying round.

The vehicles were throw-aways from an auto dealer the two knew, an important resource, since the price of scrap metal had “skyrocketed” in the past few years, and dealers therefore “want $500-$600 for a car that’s only worth it to crash up,” Rich said.

The cars must be modified for safety in the derby, which, ironically, involves removing many of their safety features.

“This car is going to lose all its safety features, [it’s] essentially brought back to its roots,” Rich said, gesturing to one of the vehicles. “This car in particular had side-impact airbags — we had to make sure they’re disabled, because if they do activate during the race, that driver is immediately disqualified.”

The cars’ windows are smashed out before the race, and an exploding airbag may harm other drivers, Rich explained.

Competitors are given a rule book beforehand, which includes necessary modifications like removing a section of the car’s hood so a burning engine can be easily accessed by the firefighters stationed around the track.

RIch (kneeling) and Noah work on a car a few hours before the competition.

Cars are modified so their essential features — the battery, the gas tank — are within the car’s center, its “safety cage,” and outside the “crumple zones” that will be compacted by other cars.

The Columbia County Fair Demolition Derby prohibits certain types of hits, Noah said.

“You can’t be hitting drivers’ doors, in case it buckles in, [and] they don’t want any head-on collisions…because then you’re frame-to-frame, you’re taking the impact, not the car,” he said.

A good method is to smash into other cars trunk-first, so your engine doesn’t sustain damage, Noah said, and, “if you knock their wheels out, they’re not going very far.”

For all the vehicular violence, the Columbia County Fair Demolition Derby is a friendly event, Rich said, where competitors trade war stories in the pit and point out features that could use improvement in each other’s stripped-down jalopies.

I asked Rich if he was ever injured during his 15 years in the derby, and he recalled one year using a large Cadillac without brakes.

“There was a guy who hit me so hard on the driver’s side I certainly needed some visits to the chiropractor,” he recalled.

After the crowd sang the National Anthem Thursday night, the firefighters hopped up and down to get their blood running as they slid on their protective gear. The announcer’s voice switched from the solemn bars of the Anthem to an enthusiastic yawp as he addressed the crowd.

“Y’all ready to crash cars?!!”

I raised my fist to the track as the crowd whooped behind me. We certainly were.