*safely (if the billboard is in an English speaking country)

"Safely" is an adverb, which as is a grammatic catch-all category.

She was vaccinated, so she died safe.

"Safe" is grammatically correct.

"Died safe" is an inherent contradiction.

"Died safe" is irrefutable fraud.

Replace every "died suddenly" headline with "died safely".

"Died safe" is a two syllable red pill.

A masterpiece.

Edit: /s/asshole the bedrock assumption of every safety study is and adverse event is/was caused by the medication/device; until proven otherwise.

Unfortunately, the opposite is the case with these injections.

Inexplicably, it is assumed that the injections are not the cause of anything

Doctors are "baffled"...

Baffels are features added to the inside of a muffler to suppress sound.
Baffles are features in a suppressors and silencers.

Doctors are baffled...
Confused.
Suppressed.
Silenced.