Bereaved children, who are spending the week at Howtown Outdoor Bound Centre with peers who have also lost a family member in the forces, say it is like being in a different world.
More top news
The fire subsequently spread to the premises next door, resulting in over £300,000 worth of damage.
Emergency services and Cumbria County Council have been called to the incident.
Alan Wilson pleaded guilty to nine offences and was sentenced to a 225 hours Community Payback Order at Jedburgh Sheriff Court.