On the fair's final day, state officials said attendance was down compared to the final weekend of last year's fair and attributed the dip partly to the injuries. They declined to elaborate on how the ride had been tampered with.
Three people remained in a Raleigh hospital on Sunday, three days after the "Vortex" ride suddenly jolted into gear as people were exiting, dropping some riders from heights that eyewitnesses estimated to be 20 or 30 feet.
Investigators determined the Vortex, known for thrilling riders with its wild twirls and flips, had been tampered with and critical safety devices were compromised, Wake County Sheriff Donnie Harrison said Saturday. Harrison's office did not return messages and officials with the state Labor Department declined to offer further explanation of the tampering and the overall investigation.
Ride operator Timothy Dwayne Tutterrow, 46, of Quitman, Ga., faces three criminal counts of assault with a deadly weapon in the mishap. Tutterrow was being held in jail Sunday on $225,000 bond and was due in court Monday for a first appearance, said attorney Roger W. Smith Jr.
"Mr. Tutterrow is absolutely devastated by what happened," Smith said in a phone interview Sunday.
Fair attendance on Friday and Saturday was down more than 11 percent compared to the corresponding days last year. While that may have been partly due to colder nighttime temperatures, the injuries probably factored into the decline, said spokesman Brian Long of the state agriculture department, which runs the fair.
"I do understand that this incident may have given some people pause," he said.
He said no further safety measures have been taken for the 100 other rides.
It is uncommon for ride operators to be criminally charged, but safety consultant Ken Martin chalks that up to the industry being largely self-regulated in most states.
"If more incidents on amusement rides were investigated as thoroughly as this ride in North Carolina is being investigated, there's quite possibly the opportunity that more criminal cases would come out. The folks in North Carolina, they don't pussyfoot around when it comes to amusement ride safety," said Martin, owner of KRM Consulting in Richmond, Va., which conducts amusement ride inspections in Texas, Virginia, West Virginia and Missouri.
The North Carolina State Fair is known in the industry for its requirement that everything on an amusement ride has to operate or the ride does not move. Several ride inspectors are on the grounds of the Raleigh event daily watching operators and equipment to make sure everything is in order, Martin said.
The people who remained hospitalized were a 14-year-old whose identity hasn't been released; Anthony Gorham, 29; and Kisha Gorham, 39. The Gorhams' family members declined to comment Sunday. The two others who were hurt have been treated and released.
The Vortex had at least one other technical problem at the North Carolina fair. A safety switch that keeps the ride from operating unless seat restraints are engaged malfunctioned on Monday. The ride was temporarily idled as workers replaced the switch, but it reopened Monday night after being tested, state inspectors said.
The Vortex was supplied by Family Attractions Amusement Co. LLC of Valdosta, Ga. The company "has never had an incident with a machine like this before," spokeswoman Joyce Fitzpatrick said.
She said the company's representatives can't explain what happened because they have not been allowed to review the inspection records, which are kept inside the ride, Fitzpatrick said. The ride has been closed since Thursday's injuries.
The Labor Department said its inspectors performed safety checks on all the rides before the fair opened. Ride operators are supposed to do three daily operational checks and record those in a log, said Tom Chambers, the chief of the department's ride inspection unit. State inspectors then perform checks of the logs to confirm operators are complying with the rules.
The U.S. Consumer Product Safety Commission recorded 875 injuries associated with amusement rides in 2012, up from 774 injuries the previous year. The cases included people who needed emergency-department treatment for injuries associated with fixed rides in theme parks, mobile rides associated with carnivals or fairs, or inflatable slides or bouncy cabins.