Four killed in US crane collapse

There have been several crane accidents in recent months

A huge crane has collapsed at an oil refinery in the US state of Texas, killing four people.

Three other workers suffered serious injuries and were taken to hospital from the refinery in Houston.

"This is a traumatic experience for all of us," said Jim Roecker of LyondellBasell, the company that runs the refinery.

Analysts say the accident will heighten safety fears after several similar tragedies in recent months.

In New York City, two separate crane accidents since March have killed nine people.

Mr Roecker, LyondellBasell's vice-president for refining, said the Texas crane, which was capable of lifting hundreds of tonnes, had been delivered in pieces and assembled on site about one month ago.

It collapsed at about 1400 (1900 GMT) on Friday.

"It's going to be quite some time before we know exactly what happened that caused the failure of this large piece of equipment," he said.

"It is certainly much too early to tell what caused the issue. But right now our focus is on those employees and their families who have been significantly impacted by this unfortunate event."

The company that owns the crane, Deep South, said it would investigate the accident "to determine the root cause, correct it and ensure that this type of tragedy does not occur again".