they look pretty dead to me. could it be extreme overwatering? the soil looks wet. did it happen fast or gradually? what's the ph? do you have dechlorinated water. also if there is no perlite added to the soil mix then the roots could be suffocating and rotting if you water alot and it doesn't have a chance to dry thoroughly. those plants are in very bad shape. if you give as much info as possible then someone can better help solve the problem so it doesn't happen again to your next grow. those plants don't look like they are gonna make it to harvest. mj is resilient so you never know but i would be supprised if those plants make it especially the second 2. good luck and i hope you have better results in the future. don't get discouraged, stick with it!!!