To provide an answer more information is needed. Please have a look at What information should I include in a question in addition to OS and LibreOffice version? - #4 by ROSt53
Depending on your settings you might be able to find a copy in your Backup folder. You will information on the location of this Backup folder under: Tools > Options > LibreOffice > Paths
I initially saved in Word format
As Impress cannot be saved in “Word” format, I interpret “Word” as MS PowerPoint format being ppt or pptx. I would not use this format, it could have been the cause of your loss. What follows are some comments about my experience and ways to avoid problems.
In respect to MSO formats, I stay always until the end in LibO native formats and only create a MSO copy of the last saved version and try to avoid the x-formats. Additionally I made the experience that a pdf-file is in most of my cases sufficient. Many people send out files in MSO or LibO or other formats when a pdf-file is sufficient. Depending on the situation you can even secure a pdf-file against copying and changees. The pdf-export function in LibO works very well. (I am using 188.8.131.52.)
In the case of presentations I am also often asked to provide a ppt or pptx copy as a fall back solution is something happens with my PC or connection of my own PC is not possible, etc. For this I always carry a USB stick with a portable LibO version on it and my presentation. All I need is PC to plug the USB stick and can run on LIbO my own presentation.
And a general comment about securing files, avoid losses. Very often I see questions on how to recover lost files. Better than attempting to recover lost data is prepare against the loss of data. To avoid a loss of a file these are 3 recommendations:
1 - Check the following LibO options: Tools > options > Load/Save > General
---- Save Autorecovery every x mins (the shorter the value the small a possible loss; I use 3 min)
---- Automatically save document too ( I don’t use this, because I regard the autorecovery function as excellent.)
---- Always create a backup copy (download and read the free of charge LibO guide to understand how this works)
2 - When I work more than a day on a file, I create additional daily back ups. I use the format “filename_yymmdd.ext” and I keep at least 1 previous version.
In case the file is extremely important and I work long hours non-stop, I add the actual time behind the date.
3 - Backup the HDD of your computer to an external HDD. External HDD in the range of 2-4 TB cost mostly less than 100 EUR. (I do this almost daily and even backup external HDD onto another one.
When it comes to this topic this expression comes to my mind: “Fail to prepare is prepare to fail!”