A high court ruled Thursday that the deaths of 23 elementary school pupils in tsunami following the March 2011 earthquake in northeastern Japan could have been prevented if the city of Ishinomaki and Miyagi Prefecture had updated a contingency plan.

The Sendai High Court ordered the governmental authorities to pay around 1.4 billion yen ($13 million) in damages to the families of the pupils, raising the amount of compensation by about 10 million yen from a lower court ruling.

The authorities "failed to fulfill their obligation to revamp a risk management manual in line with the realities of Okawa Elementary School," Presiding Judge Hiroshi Ogawa said, adding, "If the manual had designated a 20-meter-high location for evacuation" the deaths could have been prevented.

None of the courts in other tsunami-linked lawsuits have acknowledged systematic negligence on the part of the companies or schools prior to the 2011 quake.

(Pool photo)

A total of 74 pupils, and 10 teachers and officials died in the tsunami that followed the magnitude-9 earthquake on March 11, 2011. The tsunami engulfed the pupils and teachers as they began evacuating to an area near a 7-meter-high riverbank.

The ruling said it was "wrong" that the school, situated at a height of up to 1.5 meters above sea level, was not designated as being in an area that could be hit by potential tsunami in the city's hazard map at the time.

While the city claimed it was impossible to predict a tsunami that could engulf the school, which had never experienced such a disaster in the past, the ruling said that "prediction was possible and there was a risk of tsunami," citing the school's location near a riverbank.

Hiroyuki Konno, representative of the plaintiffs, said the acknowledgement of Ishinomaki city's systematic negligence was of "great significance for anti-disaster (measures) going forward."

(Then-U.S. Ambassador to Japan Caroline Kennedy visits Okawa Elementary School in September 2016)

The school revised its risk management manual in line with a law on school health and safety that came into force in 2009 but retained potential evacuation points as "vacant space and parks nearby."

Pointing to the low elevation of the school and the high risk of tsunami in the area that is close to rivers, the plaintiffs argued, "The manual was extremely inadequate as it lacked specific descriptions of evacuation sites and how to reach them. The school failed to evaluate and revise it."

The city claimed the school was only obliged to compile a manual and its content was adequate based on scientific knowledge at the time.

The plaintiffs had demanded that the prefectural and local governments jointly pay around 2.3 billion yen, arguing the school should have taken better anti-tsunami measures.

Miyagi Gov. Yoshihiro Murai described Thursday's ruling as harsh.

Ishinomaki Mayor Hiroshi Kameyama said his city is now being urged to be more involved in creating the risk management manual.

The local and prefectural governments have yet to decide whether to appeal to the Supreme Court.

In October 2016, the district court ruled that the city and prefecture were negligent, ordering them to pay compensation. The court concluded the school should have evacuated children to a nearby mountain rather than to an area near a riverbank.

The city and a third-party panel have revealed that students at the school were kept at its playground for about 45 minutes despite a large-scale tsunami warning.