Japan is set to mark the first anniversary of the devastating earthquake and tsunami which struck the north-eastern coast, killing thousands.
The magnitude 8.9 quake, the most powerful since records began, also triggered a serious nuclear accident at the Fukushima nuclear plant.
Thousands of people were evacuated as radiation leaked from the plant.
Memorial services have been planned and a minute of silence will be observed at the exact moment the quake hit.
The main memorial ceremony will be held at Tokyo's National Theatre and will be attended by Japan's Emperor Akihito and Prime Minister Yoshihiko Noda.
Warning sirens will sound across the north-east of the country today at the precise time the quake struck.
Bells and prayers will also reverberate across the country as the minute of silence is observed.
Japan's Kyodo news agency also reported that some trains in and around Tokyo will stop to mark the moment.