The low wards behind Nagoya were homes and small workshops, built on reclaimed ground that sat below the level of Ise Bay, and when Vera's surge came over the embankments in 1959 it carried the timber stored in the bay with it. The logs broke the banks in more places, and the water stayed for weeks. More than 4,500 people died there; over 5,000 in all. Japan wrote its basic disaster countermeasures law about two years afterwards.
The water didn't drain, either — parts of the Nagoya lowlands sat under floodwater for months while it was pumped out, because the ground was below the bay. People were living on embankments and rooftops that whole time.
What got through first came in by rail and water — the surviving stretches of the Tokaido line, and local ferries working across the bay where the roads were still under. Crews worked those lines for weeks with the flooding still standing.