In a memorial service with only 10 people in attendance, Tokyo on Tuesday marked the 75th anniversary of the firebombing of the city by U.S. forces during World War II that killed an estimated 100,000 people, making it one of the most deadly air attacks during the war.

The service at a hall in the capital's Sumida Ward where the remains of many of the unidentified victims of the tragedy are placed was downsized to prevent the spread of the new coronavirus. The event is normally attended by about 600 people every year.

Crown Prince Akishino, Crown Princess Kiko and Tokyo Gov. Yuriko Koike also canceled their attendance this time round. And a separate commemorative ceremony that was to be hosted by the Tokyo Metropolitan Government in the afternoon was also called off.