HAYWARD, Calif. -- A pair of lifeguards who taped a firecracker equal to a quarter-stick of dynamite to a rabbit named Lucky and threw the bunny into a lake pleaded no contest to animal cruelty after apologizing.

Nicholas K. Sigmon, 19, and Paul G. Collins, 21, had pleaded not guilty to misdemeanor animal cruelty in August. The men returned to court Wednesday, changed their pleas and were convicted.

"I learned a lesson and something like this will never happen again," Collins said in Alameda Superior Court.

The men were placed on court probation for three years, ordered to undergo counseling and directed to perform 30 days of community service.

Superior Court Judge Robert Fairwell sentenced Sigmon, who reportedly planned the incident last July, to 30 days in county jail. Collins, who filmed the incident, received a 15-day sentence. The men will serve their sentences in weekend work programs.

The men were arrested after photos of Lucky's close call surfaced on the Internet.

Fairwell also prohibited the men from owning or possessing explosives, rabbits or other animals while on probation.

The explosive never detonated and Lucky has since been adopted.