Pete Townshend is one of rock's most dynamic and charismatic personalities. But you don't want to get too close to him when he's on stage, as one well-intentioned police officer learned the hard way on May 16, 1969, in New York City.

There are more than a few tales of wild and wooly Townshend going off on folks who dared set foot on the Who's sacred stage in the late '60s. At Woodstock, head Yippie Abbie Hoffman tried to invade that territory – and caught a face full of guitar. Michael Wadleigh was filming that same legendary set and soon had a close-up of Pete's boot in his camera lens.

But before all that, at the first of the band's two shows at the Fillmore East, Townshend kicked a man off stage, apparently thinking he was just another goofy fan. Turned out he was a plain clothes policeman.

Oops.

In the spring of 1969, the Who were debuting the live version of Tommy across the United States. The band were set to perform their story of the deaf, dumb and blind boy for a weekend's worth of shows (two on both Friday and Saturday) starting on May 16 at New York City's Fillmore East.

While Pete and the boys were bringing their usual musical pyrotechnics to the stage, playing Tommy and an encore of earlier hits and covers during the weekend's first show, some fans began to notice an inordinate amount of smoke gathering in the venue. It turned out that a grocery store next door was in the midst of a five-alarm blaze. If the fire spread, it could spell disaster for everyone at the concert.

From the recollection of then-teenager Binky Philips, in the middle of "Summertime Blues," a "marine-looking middle-aged guy wearing a crew cut" tried to wrestle the microphone from Roger Daltrey. The singer punched him away, unaware of his intentions. Townshend noticed the interloper and – according to Philips' story – kicked the man in the crotch, forcing him off the stage.

Neither Daltrey nor Townshend knew this man was a plain clothes cop and had planned to get control of the mic to warn everyone about the fire next door. So, really, the man was about to yell "fire!" in a crowd. Who knows, by being the impetuous, violent young men they were, the Who members might have prevented an all-out calamity.

When they finished the song, Fillmore owner Bill Graham came out and calmly told the crowd what was happening and had them orderly exit onto the street. The blaze continued to crackle at the store, but did not spread. Out of safety concerns, the second show was rescheduled for Sunday. It was just as well. The Who would have had to go on again Friday without their guitarist, as Townshend was arrested for assaulting a police officer. (It seems that New York's finest didn't think these rock and roll heroes had really saved the day, after all.)

Townshend was released for the other four shows that weekend, and returned to New York weeks later to appear in court. Nervous that the incident could prevent the Who from touring in American for the foreseeable future, Townshend ended up with only a minor punishment. He was reportedly fined just $30 for the attack.

Given the amount of money the Who spent on replacing instruments night after night, it couldn't have seemed like much. Regardless, it certainly beats a kick in the crotch.