A powerful burst of wind in the Duluth harbor swept a small sailboat into the Aerial Lift Bridge, snapping the mast and nearly sending the vessel’s occupants into the water.

Video of the drama captured by onlookers has been viewed tens of thousands of times since it occurred about 5:40 p.m. Wednesday during the first in a series of sailboat races put on by the Duluth Yacht Club.

Bystander video showed a boat with a blue hull turning sideways and teetering as it neared the bridge deck. People on the walkway ran along, some with cellphone cameras capturing the scene.

The four people aboard the 24-foot-long vessel were scrambling to avoid being pitched into the chilly Lake Superior waters or getting conked by the falling mast.

The yacht club described the boat as a J24, a popular choice of keelboat racers, with the numerical name of “151.”

The National Weather Service in Duluth said the winds in the harbor around that time went from 9 to 25 mph, with gusts touching 38 mph, while the temperature went into free fall from 81 degrees to 48.

The yacht club said a strong current conspired with the wind to push the sailboat, which had been heading toward Lake Superior.

Club member Scott Tompkins, of Duluth, was at the helm and had three passengers with him when his craft hit the bridge.

The 61-year-old said that while the mast was about the only part of the boat that was damaged and no one was hurt, “it really was a tragic thing. It’s kind of a thing I don’t want to relive.”

One observer on one of the videos posted on Facebook can be heard giving a profanity-laced play-by-play account.

“They’re sideways … they are literally going to flip. … Oh, it broke. That sucks. … Never seen that before.”

Denny O’Hara operates a webcam that is trained on the harbor and captured not only the sailboat’s misfortune but the sudden change in the weather as well.

Even though the 65-year-old O’Hara, a photographer who shares his scenic shots at www.northernimages.com, has lived in Duluth all of his life, he said Thursday that it’s still surprising how the lake can change in an instant, “the waters were peaceful, and the forecast said the winds were going to switch, but I don’t think anyone thought it would be like that.”