Omg creepiest dream ever wat does it mean?

ok so i dont remember everything but its this one part that i cant stop thinking about....i was with 2 girls idk who they are like ive nvr seen them in my life lol and we were all at the beach...it was like around mid-day and the waves were pretty strong but it was still possible 2 swim...so we are all there playing around ( we were with the parents of one of the girls ) and this girl goes under water and a wave comes and hits her under water and she cant come back up..i tried to give her my hand but the wave just took her away and she drowned...i dont remember wat happend after that part but then we all went to her house to tell her parents and when we got there the parents we were with sent us to her room so they can tell her parents what happened so then i hear her mom scream and cry and i started crying 2 and then she comes up 2 me and the other girl and asks us what happened and even tho i knew and remembered what happened i told her "idk i dont remember"...y ?! and wat does this mean