EL MONTE, Calif.—Fourteen employees at a California aquatic center have been fired after a video posted on the Internet showed them performing a parody of a viral Korean music video.

Thirteen lifeguards and the pool manager at the municipal El Monte Aquatic Center were fired Wednesday. City officials said the video violated prohibitions on use of city property and did not meet standards for employee conduct.

"The tone and the content of the video was much less than the professional conduct that we expect of our employees," said city spokesman Robert Alaniz.

The clip, uploaded last month to YouTube, features several workers in their uniform swimsuits, mimicking scenes from Korean rapper PSY's "Gangnam Style" video.

Some dance under water and on diving boards. Other parts of the video include a line of female lifeguards rubbing sunscreen lotion on each other's backs and a male lifeguard wearing a fanny pack standing over another gyrating in an elevator.

Those who were fired said they were not on the clock when they made the video and think the city could have used reprimands or suspensions.

"I feel like being fired should have been their last decision, but it was their first decision without giving us any time to defend ourselves," said former lifeguard Michael Roa, who added that many of pool employees are college students trying to support themselves while going to school.

Others who did not actively participate in the filming, but were featured in the background, also were fired, the former workers said.