A couple of questions - have you checked for larvae to be sure that crane flies are the issue? The damage looks too severe to be crane fly alone. Have you had the soil tested for nutients/pH (same reasoning)? You may have multiple problems such as nutrients/crane fly/disease. The other possibility is the runoff, which may contain herbicides if it is coming from an agricultural area or golf course. Anything "upstream" that may be getting herbicide applied that washes down to you? The damage is so severe my hunch is that more than one thing is going on. How often have you replanted and had this loss?

Post a follow up and I'll help you figure this out. Also, contact your county Extension office and ask them about their soil testing service.

I've made some Wash Co. extension calls and finally received an email giving me testing resources...all of which sound complicated and expensive. I agree that it doesn't seem to be one thing, particularly how quickly everything died off all of a sudden. I have noticed larvae in the soil both in the lawn and garden area for years, but between me and the birds...they have been managed. I haven't re-planted other than patches and nothing establishes no matter what type of seed. I have let my lawn dry out so that I could track water run off and I get a lot from my neighbor (grass is VERY green near and along fence line). I am at the base of the mountain, but didn't notice much coming into my yard from the street drain. Poor picture attached, but it shows how it went from grass to mud (with air holes) within two weeks, so something was introduced. The thing is, I have huge worms - well fed, that is - and I thought that was a good sign of soil nutrients/quality. Fewer five-legged frogs, thankfully, but fewer lady bugs, mantis and other good bugs. My garden has been in equally poor shape, despite having raised beds. I know I'm going to have to completely dig up/re-do my yard and garden, front and back.  Are there home testing kits that you can recommend so that I can make sure I amend the soil appropriately? I can't afford high-end testing and landscaping supplies, too. Thank you for your response.

I don't know of any "kits" that are worth the money. You could do a little experimenting on your own. Take some current season grass seed and plant it in pots (or flats) containing either soil from your yard or a good quality potting soil. If the seed in the pots with your soil doesn't grow well at least you'll know that the problem is the soil, and you can investigate further. The reason to include the potting soil pots is so you know what "normal" grass growth should look like.