That is not Scotts topsoil, that is cedar bark mulch. Your seedlings are fucked, start over.

Topsoil can mean about anything- it's meant to patch up the lawn. You need a seedling starting mix with no ferts.
Cedar chips are for keeping the ground clear under your shrubbery and have NO PLACE in an indoor grow. That is what killed your seedlings, not the light, which is adequate but could be increased if you have temps under control.

You really should read the link in my sig. That stuff is important.