Erik Darling is the deceased husband of Agnes Crumplebottom. He is claimed to have drowned which is confirmed by the color of his ghost, but these questions keep piling up: Where did he die? Who is he? How did his death affect Agnes' way of life? I'm gonna try my best to answer these questions.

Who is Erik Darling exactly?

There has not been any confirmed data of Erik Darling and you really can't get anywhere without knowing his lineage. 

Where did Erik Darling die?

Supposedly, Erik and Agnes were on their honeymoon when Erik drowned. But did they really go anywhere? If we take into account that at the current time of the game's release, no other towns were made yet. So it's impossible for them to have gone somewhere for their honeymoon. Besides if he died in Sunset Valley, then we could use the Town feud to explain his death later. There is a certain lot that may have been Agnes and Erik's 'vacation home'. Yes, the house unabridged's description says it all:

"Easy living on this beach front property will make you feel like you are on vacation every day of the week"

But why is this house so important? Other than it's description giving me a hint, the fact that its the same house used as the Sunset Valley loading screen is another hint for me. So here it is: Agnes and Erik were vacationing/honeymooning at the unabridged house. This explains where Erik had died on their honeymoon.

Was Erik Darling's death really an accident?

Yes, here comes that word: Conspiracy! We all know of the feud between the Goths, Altos and Landgraabs, and we all know that the townsfolk are choosing sides but what if the Landgraab side won? Wouldn't this infuriate the evil Altos? But what does this have to do with Erik Darling's death? Agnes is sister to Corneilia who is wife of Gunther Goth whose family founded the town. Slowly loosing the town's favor, the Altos knew that they wouldn't be able to knock off a Goth (well most of them are dead 0_o) or a Landgraab without the town going crazy, so basically go after someone who has close ties with the Goths: Agnes. Agnes is the next town power after the main three families, so killing off a member will surely destroy that line. Most of the Crumplebottoms are dead and Agnes is the only one left to ccontinue the line. So the Altos went after them. I also believe that maybe Erik Darling was in pockets with them. They executed Erik Darling's drowning and left Agnes as a widow. And Agnes refuses to move on. So now her line has been destroyed if she can't marry someone else, and with the help of her dead husband to constantly to make sure that no man dare set foot on the property.  (Meaning, Erik must have been with the Altos' plot for money and power. Erik and Agnes have one opposing character trait: Grumpy (Agnes) and excited (Erik). So Erik only married Agnes for money that would be sent to the Altos. EA also gave a hint about this; in Agnes' biography the last sentence of it clearly says "only the bravest sim would ever try to win her heart and her FORTUNE." Though Erik probably wasn't aware that he would be killed in the end in his plot for money.)

How did Erik's death affect Agnes' way of life?

Everything. Agnes is basically the physical representation of mourning. Her black clothes, the unfinished nursery, it all ties in with each other. I think it's likely if we compare her to Charles Dickens' character Miss Havisham. After Miss Havisham is jilted at the altar, she literally stops time in her mansion (stopping the clocks to 8:40, the reception hall, the wedding dress, the festering cake etc.) Well Agnes doesn't really take it that far but she's on the road. Agnes doesn't want to move on from the pain though which disables her to find new love. So basically the Crumplebottom line will end with her therefore ending the Crumplebottom power.

It might be a little choppy and weird reasoning but it works for me!