Bradford suffered their heaviest defeat of the season as Crewe ran riot.
Shaun Miller put Crewe ahead after a loose David Syers pass, but the Bantams levelled through Jake Speight's penalty after David Artell had fouled him.
But Miller restored the visitors' lead after a fine Byron Moore cross, before Clayton Donaldson scored from 20 yards.
Danny Shelley then scored twice to seal the win, firing in an effort that Jon McLaughlin could not hold and then a low shot through a packed area.
Bradford interim manager Peter Jackson told BBC Radio Leeds:
"Obviously I'm disappointed being 4-1 down at half time, it's an extremely lonely place down on that touchline.
"We really wanted to go out on a high and we've not, we've whimpered over the line really.
"The best side won today and they thoroughly deserved that so full marks to Crewe.
"It could have been eight the way we were defending. It's a sad thing to say but we kept the scoreline down and thats all we could do today."
Crewe manager Dario Gradi told BBC Radio Stoke:
"It was nice to get the supporters on our side because away from home they haven't had much to shout about this season.
"it was a weird game because even at half-time I didn't think it was over, because I thought they were lively.
"Shaun [Miller] has had a super week and if he can overcome his problem of losing the ball then he will become quite a player."