Fatal accident - PHOTO: SHUTTERSTOCK

A stand-up forklift operator in San Diego, California and one of two workers in a boom lift bucket in Boston, Massachusetts have died in accidents.

In the San Diego incident, the operator died from injuries incurred when the material handling unit tipped over and crushed him at a municipal landfill.

The medical examiner's office identified the San Diego man as Lee Haleem, 42, who was moving his business and, in the process, visited the landfill.

Haleem was unloading the forklift from a Penske Truck Rental vehicle and backed the forklift over the tailgate. The fire-rescue department spokesman said the forklift tipped over although Haleem tried to hold it upright. He died within an hour at a local hospital.

City officials closed the landfill's recycling facility for several hours after the 6 February accident and initiated an investigation.

On the other side of the US, an elevated boom lift collapsed in a busy Boston neighbourhood and tossed two men from the bucket, killing James Williamson and seriously injuring Greg Johnson, according to fire department and hospital reports.

The men, employees of Reliable Roofing & Sheet Metal LLC of Framingham, Massachusetts, were inspecting the roof of a seven-story dormitory at Suffolk University. Leasing firm Height 4 Hire provided the boom lift, which a contractor cut into pieces and removed from the accident scene.

Onlookers in the Downtown Crossing area scattered as the falling boom lift touched a book store's outdoor display of paperback volumes, landed in a paved lot and partially crashed into another building. Several shoppers at the book display escaped harm in the 7 February incident.

The US Occupational Health and Safety Administration has begun an investigation.