A man died and another was severely injured on Tuesday after a mobile crane toppled and hit nearby vehicles at a construction site in Tokyo's Shinagawa Ward, according to police and firefighters.

The two were both construction workers in their 50s. The man who died was trapped inside a van parked in the construction site while the other man was in a truck parked in a street outside, they said.

The crane operator, who is in his 50s, was not injured in the incident. He was quoted by the police as saying that the crane "lost balance while lifting and moving an excavator."

The incident occurred at around 9:45 a.m. when multiple workers were around. There was no supervisor at the construction site at the time, the police said.

The police are investigating the case with an eye to building a case of negligence resulting in death and injury.

The construction site is located in a residential area, about 800 meters northwest of JR Omori Station. Firefighters were seen using heavy machinery to lift the crane.