Hull captain Dawson told BBC Sport after the game: "It is very hard. Giving them a goal so early on and we were 2-0 down at half time. With their pace, we then got caught with two more goals. The season has been a long hard slog and it is a sad day.
"The home performance against Sunderland put us in a bad position. We were chasing the game all afternoon, to get beaten 4-0 and get relegated has not gone well.
"The boys in the dressing room and the staff are very disappointed. You work hard all year and then you get relegated, you have to pick yourselves up and we know what to do in the Championship.
"Marco Silva has done a fantastic job since he came in. He has done remarkably well to give us half a chance but we just came up short."
Hull wrap up their season with a home game against Tottenham Hotspur next Sunday.