18-year-old critically hurt after horse carriage overturns in Central Park

A teenager was critically injured when a horse carriage overturned in Central Park on Wednesday.

It happened just after 2:45 p.m. near West 67th Street.

Passenger thrown from carriage

Officials said a family of four was in the carriage when the horse got spooked and took off. Police said some passengers jumped out and were not hurt.

Alexander Kemp, administrative vice president for TWU Local 100, the union representing horse carriage drivers, said it appears the driver had gotten out of the carriage to take a photo of the passengers and "was at least at arm's length from his horse."

Video shows the horse attached to the carriage running off, causing the carriage to rock onto two wheels at times. A man who appears to be the carriage driver runs after the horse.

Kemp said the carriage eventually clipped the wheel of another carriage and overturned.

 An 18-year-old man was thrown from the carriage and taken to a local hospital in critical condition.

"We are deeply troubled by reports of a passenger being injured and are wishing him a speedy recovery," Kemp said in a statement, in part.

The horse that initially ran off was found near Tavern on the Green, and was uninjured. Kemp said the horse had only been in the park for six weeks.

It's unclear what spooked the horse.

"Something happened. [The driver] said he didn't hear anything," TWU Local 100 spokesperson Christina Hansen said. "He didn't hear anything, didn't see anything. Horse took off."

Union calls incident "unacceptable"

Hansen said the driver was very shaken up by the incident.

"He's just beside himself, so he was glad to know that the horse is OK," she said. "Right now, our concern is with the customers."

Kemp called the incident "unacceptable."

"A driver is not supposed to leave the carriage to take photos – ever. We support a full investigation," he said in a statement, in part. "We also support enhanced driving training, tougher examinations with a practical component demonstrating proficiency, and rules governing the introduction of new horses into the business. Thousands upon thousands of rides are taken without incident, but steps must be taken to prevent accidents like this."

This incident comes a little more than a week after a carriage horse collapsed and died in the park. It was later determined that the horse had eaten a poisonous plant.

The Central Park Conservancy said in a statement:

"As details of today's incident come into focus, our thoughts are with the injured. That this frightening situation is just days after the previous one underscores the dangers posed by horse carriages to Park visitors, carriage drivers, and the horses themselves. The Central Park Conservancy renews its call to ban carriages in Central Park as a matter of public safety and public health. We hope today's injuries are the last we ever see."

Stay with CBS News New York for the latest on this developing story.