plant is dying - brown shrivled leafs

hey guys ,
I was away for 4 days and left my brother in charge of my 2 plants he said he watered them once. The soil seemed fairly dry when i came back . the leaves were also gone brown and withered :( anyone know why the leaves are going like this ?

thanks

http://i25.photobucket.com/albums/c8...6-30182225.jpg
http://i25.photobucket.com/albums/c8...6-30182221.jpg
http://i25.photobucket.com/albums/c8...6-30182213.jpg
http://i25.photobucket.com/albums/c8...6-30182209.jpg
http://i25.photobucket.com/albums/c8...6-30182204.jpg
http://i25.photobucket.com/albums/c8...6-30182200.jpg
http://i25.photobucket.com/albums/c8...6-24174026.jpg

I cant seem to edit the post again so il post this here :

What is your experience level?: first timer


Outdoor in pollytunnel
Is there a consistent fresh air supply :yes
Do you have an exhaust fan and a circulation fan : yes


Your medium:
peat based soil with vermiculite, perlite


Your nutrients and water:
baby bio

Your growroom:
outdoors?

Your strain:
super skunk

When is the last time you fed them? You may need to flush the soil.

Looks like a fungus possibly spread by insects. It's not dying, thats not enough light through that plastic sheeting for proper budding anyways. If it were you probably wouldn't have the fungus problem. Fail.