Investigators plan to question officials at an ordnance disposal company today to try to determine the age and type of fireworks inside a storage bunker that exploded, killing five workers and injuring another, a fire official said.

Authorities probing the cause of the explosion also want to know what the six employees of Donaldson Enterprises Inc. were doing when the blast occurred Friday and what their training was, Hono­lulu fire Capt. Gary Lum said yesterday.

The company, founded in 1988, has completed hundreds of explosive-related proj­ects with no serious accidents or injuries, according to its website.

A call to the company yesterday was not immediately returned. A woman who picked up the phone at a number listed for the company founder’s wife, Ryoko Donaldson, said the family was trying to cope and had no comment.

Authorities also plan to return to the blast site today to see whether the bunker is safe to enter for a more thorough inspection, Lum said.

"The investigator was called out and did some preliminary work on Friday, but it wasn’t safe to go in the bunker at that point," he said.

He said the bunker, which is located near the Waikele Business Center, was still warm Saturday, and officials wore protective equipment to retrieve the bodies of the last two victims.

Investigators with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, Hono­lulu police and the Hawaii Occupational Safety and Health Division were helping with the investigation.

The workers killed in the blast have been identified by family and friends as Bryan "Keola" Cabalce, 25, of Wahiawa; Kevin Freeman, 24, of Aiea; Justin Kelii, 29, of Kane­ohe; Robert Leahey, 50, brother of sportscaster Jim Leahey; and Neil Sprankle, 24, of Aiea.

It wasn’t immediately clear which government agency hired Donaldson Enterprises to store the confiscated fireworks. Hono­lulu officials said the city doesn’t have any contracts with Donaldson Enterprises.

A check on the state procurement office’s website showed Donaldson Enterprises was not listed as a state vendor nor had any professional service contracts with the state.

A call to the Bureau of Alcohol, Tobacco, Firearms and Explosives was not returned.

A spokesman for the U.S. Customs and Border Protection said, generally speaking, the agency will seize illegal goods and turn them over to a private contractor to hold until the case is adjudicated.