3 U.S. soldiers found dead in Lithuania; 1 still missing after vehicle is swallowed by peat bog

[Laha]

3. No reports that I know of

But my guess from clues in the article,

"Earlier this week, the U.S. Army said hundreds of soldiers and law enforcement personnel, American and Lithuanian, scoured the thick forest and swampy terrain to find the missing soldiers."

That last sentence suggests at least one of the bodies was definitely not found in the vehicle. By the size of the search effort deep into the forest suggests they weren't expecting to find the fourth body washed up on shore.

Sounds like they didn't drown in the vehicle to me.

All speculation.