A man in his 60s apparently fell into a 30-meter-deep oil tank Tuesday while operating heavy machinery at a construction site near Tokyo, police said.
The man was placing dirt around the oil tank at the site for a park in Yokohama's Kanazawa Ward when the accident took place. There were no fences around the oil tank, the police said.
A local fire department received a report of the accident at around 4:15 p.m. Police and rescue workers had to suspend their initial rescue operations as night fell, citing the risk of further accidents in the dark.
The authorities plan to resume their search on Wednesday morning.