OAKLAND TWP -

Penny by penny, children at a suburban Detroit elementary school have raised $4,500 to help a Marine Corps combat veteran get a new service dog.

Eric Calley of Lansing has post-traumatic stress disorder and lost his service dog Liberty to cancer in January.

Students at Musson Elementary School recently held a penny drive to help pay for a replacement for Liberty. 

 Calley spoke at a school assembly Thursday, thanking the children for their help. Musson Elementary is on Oakland County's Oakland Township.

Calley says he's "humbled that the elementary school raised that much money" to help him with his issues.

 He says that "service dogs ... do something that's so great for ... veterans and servicemen and women."