State Department officials said the investigation and the closing would last at least several days.

The previous investigations have lasted for more than five years until now (May 2013) and are still without any result.

Such investigations, she said, can last six weeks and cost $150,000.

No one knows how long the pending investigations will last.

He predicted the investigation would likely last as long as the President was in office and beyond.

He'd keep looking - it seemed that his investigation would last two or three weeks, the way he was going.

Even though the formal investigation would last for several months, the case was effectively closed less than nine hours after it had begun.

Although the investigation into the crash lasted two years, a cause was never determined.

The investigation covered the period from 1939 to 1989 and has lasted for five years.

The investigation into the case has lasted nearly six months.