INCHEON, South Korea—When North Korean artillery shells started slamming into Kwan Young-hee’s small island village Tuesday afternoon, she grabbed her cellphone and ran for her life.

A girl arriving with her grandmother at Incheon from Yeonpyeong island Wednesday.

“The noise was so loud, the whole house was trembling. All the windows shattered,” said Ms. Kwan, who crammed with dozens of her neighbors into a concrete civil defense bunker as the bombardment continued.

Two civilians and two South Korean marines were killed by the roughly hour-long barrage, which rained about 170 shells onto South Korea’s Yeonpyeong Island, according to the government in Seoul. It also shattered the aura of peace surrounding an area that for many residents seemed far away from any conflict, despite the island’s proximity to disputed waters and the longtime presence of South Korean troops.

On Wednesday morning, Ms. Kwan and nearly all of the island’s other civilian residents—most of whom make a living fishing and farming—were evacuated aboard a South Korean coast guard vessel.

Emergency services personnel inspect inspecting damage on Yeonpyeong island Wednesday, in a photo handed out by South Korean officials.

The villagers, who arrived in the port city of Incheon Wednesday afternoon, described scenes of devastation. Shells started fires that spread quickly, incinerating houses, they said.

“Nothing like this has ever happened before. It was such a peaceful place,” said Ms. Kwan, 47 years old. “Now I don’t want to go back.”

South Korean television aired images of the shattered village, showing the toll the barrage took on civilian buildings as well as the island’s military base…