Details were sketchy about the child and the injuries he received at Idlewild and SoakZone in Ligonier around 1 p.m.
He was airlifted to Children's Hospital in Pittsburgh about 50 miles away, said Westmoreland County public safety spokeswoman Mary Beth Eslary. A hospital spokeswoman said the parents have asked that no information be released about the child or his condition.
In the other recent accidents on amusement park or fair rides across the country, one child has been killed, another suffered a brain injury and at least two others were hospitalized.
Idlewild and SoakZone spokesman Jeff Croushore provided few details regarding the accident, but said it happened on the Rollo Coaster, an old-style wooden ride, CNN-affiliate WTAE
The boy fell off about midway through the ride, according to Eslary.
Croushore said the boy, who was riding with his brother, was alert and talking after the fall.
The roller coaster, which was built in 1938, does not include seat belts and has a height requirement of 36 inches; riders under 48 inches must be accompanied by an adult, according to the park's website.
The coaster was inspected August 6 and passed, according to the Pennsylvania Department of Agriculture, which oversees the state's 10,200 amusement rides. The department is now investigating the accident, and it will re-examine the inspection history, said Logan D. Hall, spokesman for the department.
The Rollo Coaster will be closed pending the results of the investigation, Croushore said.
A pair of inspectors from the Bureau of Ride and Measurement Standards, part of the agriculture department, arrived at the park at 7 a.m. Friday, according to bureau director Walter Remmert.
Recent accidents spark investigations
The Pennsylvania accident comes after several others across the nation.
A 10-year-old boy died
on a water slide at the Schlitterbahn Water Park in Kansas City, Kansas, on Sunday. Two riders were injured
when a launch cable detached at Cedar Point in Sandusky, Ohio, that same day.
Three children fell from a Ferris wheel
at a Tennessee county fair on Monday, critically injuring two of them.
On Thursday, a 6-year-old girl remained in critical condition with a brain injury and a 16-year-old girl had been upgraded to stable condition.
The ages and conditions of the victims in the Ohio accident were not immediately released.
The Kansas City accident, which killed the son of a state legislator, remains under investigation with few details released.
Authorities in Greene County, Tennessee, cited a mechanical flaw for causing the Ferris wheel gondola to tip and spill the girls out at the county fair.
The Kansas water slide passed inspection two months ago, according to state records. Park guests said the slide's harness wasn't working properly the day Caleb Thomas Schwab died.
There are an average 4,423 injuries in amusement parks each year and 20 injuries daily from May through September, the parks' busiest time, according to data from a study by the Nationwide Children's Hospital
in Columbus, Ohio.
About 30,000 of the cases involved those under age 18.
Data showed that even mall rides could be dangerous.
"Many of the injuries on these rides are over hard floors, and children are falling on a hard floor and are ending up with head injuries," said Tracy Mehan, lead researcher on the study.
The 2013 study used Consumer Product Safety Commission information on children and teens who were taken to emergency rooms for amusement ride injuries over 20 years.
The injuries ranged from head and neck problems to injuries to the face, arms and legs. Soft-tissue injuries -- damage to ligaments, muscles and tendons -- were the most common.
Injuries considered serious made up a small percentage.
What steps can parents take to keep children safe
The study authors noted that parents can help keep children safe by following a few guidelines:
• Make sure to follow any special seating order and/or loading instructions.
• Always use safety equipment such as seat belts and safety bars.
• Make sure children keep hands and feet inside the ride at all times.
• Know your child. If you don't think he/she will be able to follow the rules, keep him/her off the ride.
• Trust your instincts. If you are worried about the safety of the ride, choose a different activity.
• Avoid "mall rides" if they are over a hard surface or if they don't have a child restraint such as a seat belt.