Hearing Loki's anguish made Thor's heart tremble and visibly wince behind the door. "Brother.." He began but faltered right there. He opened the door slowly, almost not wanting to come in. The sight before him made the warrior's breath catch in his throat. He stumbled clumsily over his own feet in his mad dash over to his brother. He couldn't even look Loki in the eye as he wrapped his beefy arms around his small brother gingerly, afraid he would break him even more. 

"Brother.." He began his speech again, "I would have released you from your prison if I was able to...I'm so sorry. No, mother's death is in no way your fault. At best...its mine..and our father's. She died protecting her land, it was a noble death...but that doesn't cause it to hurt any less I know." He finished by holding Loki a bit tighter, hoping to provide some sort of comfort.