Why was 'Tommy' deaf, dumb, and blind?

"British Army Captain Walker is reported missing in action during World War I, and is not expected ever to be seen again. Shortly after his wife, Mrs. Walker, receives this news, she gives birth to their son, Tommy."

"Seven years later, Captain Walker returns home and discovers that his wife has found a new lover. The enraged Captain Walker confronts his wife and kills her lover. Tommy witnesses this through his mirror. To cover up the crime, Tommy's parents tell Tommy that he didn't see it, didn't hear it, and he will say "nothing to no one ever in [his] life". A traumatized Tommy takes this literally, becoming deaf, dumb, and blind."


https://en.wikipedia.org/wiki/Tommy_%28rock_opera%29

I thought Captain Walker is the one who gets killed.

"Tommy follows him to the bedroom where Walker sees Mrs. Walker and Hobbs in hot passion, Hobbs kills Captain Walker by smashing a vase on his head, which is witnessed by the young Tommy. Tommy is then told in a violent manner that he "didn't hear it, didn't see it" and "won't say nothing to no-one," and as a result becomes deaf, mute, and blind. Hobbs and Tommy's mother turn to such characters as the preacher (religion), the Acid Queen (drugs), and doctor (medicine) for cures to Tommy's condition."

Copied from Wikipedia

NOTE: In the film version of the song, Pete Townshend changed the time that the song takes place from 1921 to 1951 and instead of Capt. and Mrs. Walker killing the lover, Mrs. Walker and the lover kill Capt. Walker.


https://en.wikipedia.org/wiki/1921_%28song%29