A charity stunt that has grown into a social media phenomenon went terribly wrong for four Kentucky firefighters when a fire truck's ladder got too close to a power line after they dumped water on college students who were taking part in an "ice bucket challenge."

Campbellsville Police Chief Tim Hazlette said the power line was never touched Thursday morning, but it carried such a high voltage that it was able to energize the ladder truck, shocking the firefighters.

The two in the bucket were at a hospital burn unit early Friday. One was in critical condition and the other was in fair condition, the hospital said. The other firefighters were treated and released.

The firefighters had just taken part in the challenge that helps raise money for ALS research. They dumped water on the Campbellsville University's marching band, but most of the students had already left the area and no students were hurt.

University nursing student Julie Smith said she was nearby and spoke to a couple of friends who witnessed the firefighters being shocked and said "they are taking it really hard."

"It's tragic, I feel for all the band members who were still there when it happened, that they had to see that," Smith said. Smith later led a prayer vigil with about 100 people on the campus Thursday night.

Power was knocked out for about an hour to 4,500 customers, including the school, said Natasha Collins, a spokeswoman for Kentucky Utilities, which owns the line.

The ice bucket challenge has been sweeping social media websites. The ALS Association said it has raised more than $41 million.

Police said Capt. Tony Grider, 41, and Simon A. Quinn, 22, were in the fire truck bucket. Grider, a 16-year veteran of the department, was in critical condition at the University of Louisville Medical Center Burn Unit. Quinn, a part-time firefighter, was listed in fair condition there.

Firefighter Keith Bricken, who has worked with Grider for about three years, said he was a tough firefighter who trained colleagues.

"He's real outgoing. He loves to help in any way he can," Bricken said.

Also injured was Capt. Steve Marrs, 37, who has been with the department for 11 years, and Alex Johnson, 28, who has been there three years.

Campbellsville University, a private college, is a Christian institution that has about 3,600 students, according to its website. It is about 65 miles south of Louisville.

"A number of our students, of course, the entire marching band, witnessed the event and so we're concerned about them and the tragedy of this accident," university president Michael Carter told WHAS-TV (http://bit.ly/1nfKGZ6 ).