Southend were relegated from the Championship after defeat to rock-bottom Luton.
The Shrimpers needed a win to maintain any realistic chance of staying up but they went behind after 20 minutes after Calvin Andrew controlled and shot home.
Matthew Spring rifled home a second on 39 minutes from David Bell's cross.
Lee Bradbury pulled one back after a goalmouth scramble but Besian Idrizaj wrapped it up when he raced onto Spring's clearance and slotted in.
Southend manager Steve Tilson on their relegation:
"It wasn't about this match, our last three or four home games have cost us.
"This game was the final nail in our coffin, if we had won as it turns out it wouldn't have made any difference.
"In the first half they had three shots and scored two, and we had three shots and scored none."
Luton manager Kevin Blackwell:
"It was a good professional performance. This win has been coming, although we'd have liked it sooner.
"I've been looking towards next season since day one really.
"The last time I had a team as young as this was Huddersfield's youth team, but that can only be good for the future."
Southend: Flahavan, Francis, Clarke (Prior 90), Barrett, Hammell, Moussa, Maher (Hunt 31), McCormack, Campbell-Ryce, Bradbury, Foran (Ademeno 81).
Subs Not Used: Collis, Sodje.
Booked: Barrett, McCormack, Bradbury, Clarke.
Goals: Bradbury 66.
Luton: Brill, Foley, Coyne (Langley 82), Barnett, Emanuel (Davis 61), Spring, O'Leary, Bell, Heikkinen, Andrew (Talbot 78), Idrizaj.
Subs Not Used: Keane, Brkovic.
Booked: Andrew, Barnett, Heikkinen, O'Leary.
Goals: Andrew 20, Spring 39, Idrizaj 87.
Southend are relegated
Ref: S Tanner (Somerset).