Sparks fly from circus performer's crotch during St Patrick's Day morning-news segment

An American morning news show got a full-on St Patrick's Day surprise when a risqué circus performer put an angle grinder on her metal-plated pelvis and let rip.

"Boy, what a treat we have for you today," said reporter Pat Tomasulo from Chicago's WGN morning news show.

The treat was a performance from circus freak-show performer Shana Vaughan-Gabor who works with the burlesque troupe Cirque de la Femme.

"I'm not entirely sure what it is but it involves a power tool," Tomasulo said when Vaughan-Gabor, dressed in little more than a corset and thigh-high stockings, prepared to dazzle with her powered-tool display.

"I'm gonna let you just do it and marvel at whatever it is that you're doing," the giddy reporter said.

Something else Tomasulo did not know was that Vaughan-Gabor was a professional dominatrix nicknamed 'Pussysparks'.

The performer struck up the grinder and stuck it down on her metal-plated girdle.

Sparks flew on and off camera as astounded viewers and the show's producers wondered what they were seeing.

A small number of children, some barely in their teens, also wondered what was going on and watched on with curious and impressionable minds.

The show's anchor could be heard throughout the display asking "What the hell is going on?" when things went up another notch.

Vaughan-Gabor flipped into a headstand on a chair, spread her legs out and slammed the grinder down between them on the metal plate atop her g-string.

The show quickly cut away to sports news.

Immediately after the performance, anchor Larry Potash tweeted his apologies for the "unintentional porn that just aired".

Tomasulo tried to save face after the show, appearing with the kids and asking what they thought of the lady "shooting sparks out of her midsection".

As one girl demonstrates to the camera, their little minds were blown.