Can a brain hemorrhage be caused by injury ?

my cousin who is 16 had a brain hemorrhage, could it have been caused by an injury because earlier that day she fell and banged her head very hard on concrete she was unconscious, we took her A&E they said it was mild concussion and sent her back home later that night she complained of the most excruciating headache she ever felt and again become unconscious, after CT scans they found out she had a brain hemorrhage, i was just wondering if this was caused spontaneously or if it was caused by the injury ?