SALT LAKE CITY — Several thousand people attended a Halloween party near Utah Lake on Saturday night, days after organizers claimed their event had been canceled.

Police say it was one of two parties in Utah County on Halloween night in which more than 1,000 people attended.

The Utah County Sheriff’s Office said deputies responded to a large party on the west side of Utah Lake, south of Saratoga Springs near the Knolls about 10 p.m. Sheriff’s Sgt. Spencer Cannon said “several thousand” people were in attendance, with the estimates from those who were there ranging from 2,000 to 10,000 people. The party included a stage, a professional sound system and lights, and DJs.

Cellphone videos of the event posted on social media show people, who appear to be high school or college age, packed together in a large group with no social distancing and very little mask wearing.

Cannon said deputies found out about the unauthorized event, in part, because medical crews were called to the scene after a woman who was crowd-surfing fell and hit her head, knocking her temporarily unconscious. A medical helicopter was initially preparing to go to the scene before emergency responders decided to take her to the hospital by ambulance, Cannon said.

There were also several crashes as the crowd tried to leave the area, he said. One social media post appears to show a car ending up on the top of another vehicle.

Cannon described the organizers of the event as cooperative once they were told to shut down. No one was arrested, but Cannon said criminal charges would be considered against the organizers for hosting a mass gathering without a permit.

Investigators say the event was hosted by The Tribe Utah. On Instagram, both The Tribe Utah and Utah Tonight posted videos of the event.

This comes just a week after Utah Tonight announced it was canceling an event it described as the biggest Halloween party in Utah. For a month, both Utah Tonight and The Tribe Utah had advertised an event called “The Protest on Halloween,” with the location of the event being announced on Saturday. As part or the promotion for the “full concert production,” organizers posted on their flyers “gatherings are essential for public health” and that by attending, “you assume all risks associated with COVID-19.”

But on Oct. 26, after their event had gained public attention, the groups announced that the party had been canceled and refunds would be given. In announcing the cancellation, Utah Tonight blamed those “in positions of power and authority, including the media, (who) have done nothing but intimidate, harass, and seek to build consensus to shut this event down.

“We find it both disheartening and concerning that some within our society have allowed fear to supplant basic rights of assembly, giving individuals within the media and some public servants the ability to control what we consider to be a ‘pursuit of happiness,’” the group said in their prepared statement.

Utah Tonight argued that the guidelines for managing gatherings in Utah are inconsistent and the rules for who can have an event are subjectively applied, and that the 18 to 25 age group was unfairly being singled out for spreading the virus.

Both Gov. Gary Herbert and the Utah County Health Department on Sunday reacted to the party, again stressing that the social gatherings are still the main source of COVID-19 infections.  

“As we struggle in our local and statewide communities to contain the COVID-19 virus and mitigate its impacts on our communities, it is unfortunate that some would ignore public health and medical guidance and plan and participate in an event that would allow for the ready spread of the disease between individuals which can then be taken back by these individuals to our communities and infect others who are trying to follow public health and medical recommendations,” the health department said in a prepared statement.

“The organizers of the Halloween Protest are encouraging the direct opposite of public health and medical guidance. They claim to want to get life ‘back to normal.’ Their actions and the actions they are encouraging will cause a further increase in COVID-19 cases and push the time of ‘back to normal’ that much further away. The actions of the organizers and attendees are dangerous to themselves, our communities, our health care system, and our efforts to combat COVID-19.”

Health officials encouraged those who attended the event to monitor themselves for symptoms of COVID-19 and get tested if any of those show up.

Also Saturday, Lehi police say they responded to a warehouse near 400 South and 850 East in their city and found an estimated 1,500 people attending a party. Police say they don't know who hosted the event. But because of noise complaints and having too many people in violation of the fire code, officers shut it down. Lehi police noted, however, that the group was extremely cooperative with officers.