'Sudden thermal gust of air' to blame for Williams hot air balloon going haywire

Several people were hurt on Saturday after high winds tossed a hot air balloon onto people and property at a fair in Williams, Arizona.

The Fourth Annual Independence Day Craft Fair, benefiting the Williams area Habitat for Humanity, started fine, but high winds grabbed a hot air balloon loaded with propane just before noon on July 6.

The wind flung the balloon around the ground, hurting several people. The balloon also damaged cars, light poles, electrical connections and blocked a roadway.

Witnesses said a junior marine, part of a group helping with the balloon rides, was injured, along with a little girl. A woman who was holding the rope also had serious injuries to her arm, requiring treatment at a trauma center.

"They were all transported to Flagstaff Medical Center. Injuries included a broken thumb and rope burns for the 8-year-old female, and back and neck injuries for the 15-year-old male. The adult female sustained abrasions," Williams Police said in a news release.

So, what caused the balloon to fly up in the air?

Williams Police said, "The Pilot, identified as Dwayne Osborne reported that initial wind speeds were around 7-8 miles per hour, but a sudden thermal gust of air escalated winds to 40-50 miles per hour, leading to the balloon detaching from its anchor point and colliding with nearby structures and vehicles. There was no passengers in the balloon."

The Federal Aviation Administration was notified of this incident.

Although no one was inside the balloon's basket, the fair was offering tethered hot air balloon rides before the incident happened.

'They're largely an unpredictable but common event'

Meteorologist Brian Klimowski with the National Weather Service in Flagstaff said the forecast indicated ballooning would be safe.

"Yesterday the forecast was for warm with winds anywhere from 10, maybe gusting to 25 mph. There's nothing within that forecast that would keep me from taking a ride in a hot air balloon," he said.

Ballooning expert Pat Cannon agrees.

"You have a beautiful day and the winds are light, and you have an opportunity to inflate your balloon and you do so. Now, we don't generally fly balloons in the middle of the day, but it is possible to at least inflate a balloon in the middle of the day for advertising purposes or for any other purpose for that matter."

But, then a dust devil tore through the area.

Klimowski says the weather phenomenon happens regularly on sunny days in this climate.

"We can't detect them though with our radar or with our surface instrumentation, so they're largely an unpredictable but common event," Klimowski said.

Cannon said he's experienced the unforgiving nature of a dust devil before.

"If it does form like it did for me many, many years ago, it twisted the balloon around when it was lying on the ground. In fact, the mouth of the balloon wasn't even open, it was simply lying on the ground, and it picked it up and twisted it around and threw it back down on the ground again," Cannon said.

While Cannon said hot air balloon rides should not be thought of as unsafe, he does want people to stay vigilant when at ballooning events.

"Even a balloon that's inflated that may be moving toward you is something you want to be careful of because it represents several tons of movement of an object through the air," he said.