A 19-year-old volunteer firefighter described by an Ocean County law enforcement official as a "serial arsonist" was sentenced to 11 years in prison Thursday.

Ryan Dellane, of Manahawkin, who was in training with Stafford Township Volunteer Fire Department when he was arrested, pleaded guilty earlier this year to setting nine separate fires. One of the fires -- in March 2010 -- spread across more than 500 acres in the Pine Barrens and caused the evacuation of residents in two towns.

In his confession to investigators, Dellane admitted that be began setting fires only two months after joining the fire department in 2008. He went on to commit 25 fires, said Ocean County Executive Assistant Prosecutor Michael Paulhus.

The courtroom in Toms River was packed with firefighters and Dellane's friends and family, who offered conflicting testimony of a young man who spent his spare time volunteering for local charities but also snuck out into the woods to light fires that he later would help put out.

New Jersey Forest Fire Service Section Warden Donald Knauer testified how a group of firefighters was almost killed fighting one of Dellane's fires.

"Knowing the fire he lit injured a firefighter, Ryan still lit the next fire," he said. "It was heartbreaking. Ryan was never a firefighter, nor will he ever be. He is a serial arsonist."