Updated

A South Carolina teen has been ordered to spend 15 years in prison for setting a fire that killed his 14-month-old stepbrother.

Several media outlets report that 17-year-old Jacob Morgan accepted a deal from prosecutors Tuesday, pleading guilty to involuntary manslaughter and unlawful neglect of a child.

Prosecutors say Morgan set a fire in March at a Rock Hill mobile home that killed Joshua Hill. State police say the fire was intentionally set in two places, each by heat sources.

But Morgan's family says they think the teen is innocent and did not set the fires on purpose.

Morgan's lawyer says this is one of the hardest cases he has had to defend and the teen is a gentle soul who will struggle behind bars.