West Ham boss David Moyes urged perspective from fans after their 6-0 thrashing by Arsenal.
Home supporters began leaving at halftime with Arsenal 4-0 ahead.
"To be a football supporter and especially at this club - I came back twice to keep them out of relegation - there's always going to be bad times," said Moyes.
"It was only a few months ago we were having probably the best time West Ham have ever had. I'll take a bit of time and see if I can fix it.
"I totally understand them [the fans] leaving but at football clubs you're going to have bad days. I certainly wouldn't forget the good ones."
He also said: "I'm not used to my team conceding the goals like we have been.
"We have no real reason to say why that should be happening. For some reason we didn't look like we could defend today."