Updated

A monorail accident early Sunday morning killed a train operator at Walt Disney World in Orlando, Fla., according to emergency officials.

One train rear-ended another at about 2 a.m. EDT on the EPCOT track near the Disney World parking lot as people were leaving the park following a Fourth of July fireworks show, witnesses told local cable-TV news channel Central Florida News 13.

Bo Jones, deputy chief for Reedy Creek Fire Department, says one train operator died at the scene of the crash.

The other train operator was not injured, but was taken to a hospital because he was emotionally shaken. Five park guests were treated at the scene.

"Today, we mourn the loss of our fellow Cast Member. Our hearts go out to his family and to those who have lost a friend and co-worker," read a statement from Walt Disney World Vice President of Public Affairs Mike Griffin.

"The safety of our guests and Cast Members is always our top priority. The monorail is out of service as we continue to work closely with law enforcement to determine what happened and the appropriate next steps."

Jones says it is unclear what caused the crash. Orange County Sheriff's officials are investigating the cause.

About a dozen guards wearing blue Disney security uniforms guarded the monorail station Sunday morning and prevented visitors from approaching the area.

Ethan Meus, who was visiting the theme park from Dubuque, Iowa, said he and his family took the monorail to dinner at a resort hotel Saturday night.

Meus, 17, watched the Magic Kingdom fireworks from the monorail on the way back to his hotel, he said, and didn't notice any problems with the train.

"It's pretty shocking to hear that a driver was killed in that accident," Meus said.

The family was planning to take the train again Sunday to visit Disney's EPCOT Center, but now planned to take a bus, Meus added.

"You would think it would be so safe," said 20-year-old Lauren Shoebottom, who was visiting the park from London. "You don't expect it on holiday, do you?"

According to Central Florida News 13, it was the first fatal accident in the Disney World monorail's 38 years of operation.

According to MyFoxOrlando, Disney World has 12 monorail trains, each with 6 cars traveling the 14.7 miles of elevated rail throughout the complex.

"It's a bit shocking," said 22-year-old Danielle Williams, of London. "Disney seems so perfect."

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The Associated Press contributed to this report.