Was fishing on the Fox River in Algonquin. Heard what sounded like a jet-ski jumping and making some odd noise, but thought nothing of it until firetrucks and rescue vehicles started showing up along the river upstream. The loud sounds we had heard make sense in retrospect, it was the sound of the boat’s propeller as the boat went airborne. It had hit the first pier which acted like a ramp and launched it and flipped it in the air, then it landed in the up-side-down position as you can see in the video. Accident happened when it was still dark out, we took to boat upstream to a different fishing spot and this is what we saw. Here’s a link to the official news story: chicago.cbslocal.com