(TNS) — A 9-year-old girl was in Hersheypark’s wave pool before she died Thursday, the park confirmed.

Derry Township Police Chief Garth Warner confirmed the girl had fallen unconscious before being rushed to Penn State Health Milton S. Hershey Medical Center, where she died. Her name and cause and manner of death have not been released.

“The Shore” wave pool remained closed on Friday out of respect for the girl and the workers who tried to save her, Hersheypark spokeswoman Quinn Bryner said in a statement.

Hersheypark did not respond to messages asking for confirmation, but it appears the girl’s death was the first at The Boardwalk, which opened 18 years ago, and likely the first for a guest in the entire park’s 119-year history.

A witness told WGAL they had just arrived at the wave pool about 6:45 p.m. Thursday, when it was still 92 degrees and they “saw a child being pulled, limp, from the wave pool.

“Lifeguards blew their whistles, evacuating everyone, and within moments, staff and security rushed to help.”

A male lifeguard intently performed CPR for several minutes, then stopped, “’clearly shaken,” the witness said, prompting audible sighs from the crowd.

“Staff did their best to shield onlookers from the trauma, but the weight of the moment was overwhelming,” the witness said, according to WGAL.

While the girl’s death was the first of a guest, a Hersheypark employee died in an accident at the park in August 1977. The 16-year-old maintenance worker was struck and killed by a roller coaster train while pulling a switch on the tracks of the SooperDooperLooper. The train lurched forward, running him over and causing massive chest trauma to the Lebanon teen.

The wave pool opened in 2009 and contains 378,000 gallons of water that goes into periods of waves every ten minutes.

Bryner said there were 10 lifeguards stationed at the wave pool at the time the child went into distress. She would not say how many guests were in the wave pool or whether they were at capacity.

The park’s website says: The Pennsylvania Department of Health has instituted a maximum number of allowed guests in each of our aquatic attractions. Bryner did not say what that number was for the wave pool.

When each attraction reaches its limits, a line forms. “Riders enter and exit attractions via designated points. As guests exit the attraction, additional guests will be permitted to enter.”

Hersheypark lifeguards recognized the girl needed help and tried to resuscitate them, Hershey Entertainment & Resorts Company CEO John Lawn said in the statement.

Bryner said the lifeguards stationed at the wave pool receive the highest level of water safety training available through Ellis & Associates, the agency that trains and certifies Hersheypark’s lifeguards.

According to Bryner, “special facility training” for the wave pool includes: deep-water lifeguarding, basic life support, AED use, supplemental oxygen support, CPR and first aid.

Warner said his police department is assisting Hersheypark and the Dauphin County Coroner’s Office with collecting evidence and putting together what happened before the girl’s death.

Police will document the scene, talk to witnesses and anyone who tried to save the girl, and review any cellphone or body camera footage. It’s unknown how long the investigation will take, Warner said, depending on how quickly investigators can gather evidence and complete interviews.

“We are still in the early stages of this process, and we are working to gather all of the facts in the incident,” police said in a statement. “Our thoughts and our hearts are with the family and friends of this young life, lost too soon.”

Hersheypark has 19 lifeguard instructors and one instructor trainer, Bryner said.

Hersheypark’s website says complimentary life jackets are available for guests on a first-come, first-served basis. Guests are also allowed to bring their own jackets as long as they are Coast Guard-approved.

Hersheypark opened on Memorial Day, May 30, 1906, featuring its original main buildings, a rustic bandstand and a pavilion that served as a stage for vaudeville and theatre productions.

In 1971, the park started a five-year conversion from a regional amusement park to one of America’s most popular theme parks.