Survivors said the small sightseeing boat had almost finished an hourlong night tour of the Hungarian capital on Wednesday and was nearly at its stop when a larger cruise ship hit it under a bridge. They said about 20 people were on the deck taking photographs or preparing to disembark. The others were in the cabin.
"I saw that big cruise ship coming closer to us but I never imagined it would ram our boat," a South Korean surnamed Jeong was quoted as saying by the Yonhap news agency.
Let our news meet your inbox. The news and stories that matters, delivered weekday mornings.
Jeong, 31, said she and others on the deck were thrown into the cold Danube waters by the impact of the collision. Police said it took only seven seconds for the boat to overturn and sink.
She said she saw a lifeboat drifting near her and managed to get hold of it. She threw a rope to another South Korean tourist surnamed Yoon, who was near her.
"Our boat was turned over in an instant and began sinking," Yoon, 32, told Yonhap. "All those on the deck fell into water and I think those staying in the cabin on the first floor probably couldn't get out of the ship swiftly."
While holding onto the lifeboat together, Jeong and Yoon said they shed tears when they saw the heads of other people coming up and down in the fast-moving river.
"The people had been plunged into the river in the darkness and shouted, 'Help me!' while floundering in the waters. But I couldn't do anything for them," Jeong said, crying.
Another survivor surnamed Ahn, 60, said a crew member of another sightseeing boat sailing nearby extended a hand to him after he was tossed into the river. But he lost his grip and was carried away by waters before he got hold of a drifting plastic object.
Yoon said she saw the cruise ship that rammed her boat keep sailing without stopping to help with the rescue after the collision.