Premier elements crashed and lost video - now it wont open

Could you please share the complete system details with us. You can open command prompt and run following and share the systeminfo.txt file generated with us. 

systeminfo > C:\Users\<Username>\systeminfo.txt

Also, what was the media type you were using in the project and broadly what all operations you performed. Also, could you please delete contents of the following folder and try reopening the project - 

- C:\Users\<Username>\AppData\Roaming\Adobe\Common

- C:\Users\<Username>\AppData\Roaming\Adobe\Premiere Elements\18.0

- Go to the folder where you saved the project and delete folders with the names "Video Previews" and "Layouts"

Also, would it be possible for you to share the project file with us. 

You can try opening the previously auto saved projects present at the same location where you have saved your original project.

Best,

Anubhav

You have my sympathy.   Based on my personal experience it is more likely you had a hardware failure than a software failure.  Of course that doesn't help.   

Premiere Elements automatically creates backup project files.  I think the default is every 15 minutes and it keeps five.  Make a copy of one and try opening it.  They will be in a folder withing your project folder.  The folder should be called "Premiere Elements Auto-Save".