chujiten: 街は強風にあおられて火の海と化した.　 A strong wind was blowing and the neighborhood turned into a sea of flames.
luminous: 1 階は火の海だった The 「first [《英》 ground] floor was 「a sea of flames [in flames].
prog: 部屋の中は火の海だった The room was 「in flames [a sea of flame/ablaze].
      繁華街は火の海と化した  The shopping district turned into a blazing inferno.

I think it's clear enough that "sea of fire" isn't literal, especially with the id tag.

@@ -14 +13,0 @@
-<gloss>area engulfed in flames</gloss>
@@ -15,0 +15,2 @@
+<gloss>sea of flames</gloss>
+<gloss>blazing inferno</gloss>

sankoku:
火事で、いちめんに火がもえ広がった状態。「あたりは━だ・空襲で東京が━になる」

@@ -12,0 +13,2 @@
+<misc>&id;</misc>
+<gloss>area engulfed in flames</gloss>
@@ -14 +15,0 @@
-<gloss>sea of flame</gloss>