Updated

More than a dozen family members of miners killed in a southeastern Kentucky mine explosion protested a closed-door hearing Wednesday held by state officials investigating the blast.

Tracy Stumbo, the state's lead investigator in the blast, and other officials began interviewing about 25 employees and executives of Kentucky Darby LLC. The May 20 blast at the Darby Mine No. 1 killed five miners; a sixth was rescued.

State officials rejected a request earlier this week that representatives of the miners' families have access to the interviews and be able ask the witnesses questions.

"If they've not got anything to hide, why don't they let us in to listen?" said Tilda Thomas, whose husband, Paris Thomas Jr., was among those killed.

Natural Resources Commissioner Susan Bush said Tuesday that the state needed accurate information quickly and wanted witnesses to be as comfortable and forthcoming as possible.

The widows and other relatives stood outside the building where the interviews were conducted, wearing black ribbons commemorating the fallen miners and holding signs that read, "Company reps in, family reps out, WHY!?" and "Governor, what's there to hide?"

Four of the five families are being represented by attorney Tony Oppegard, former general counsel for the state Office of Mine Safety and Licensing, and Kenny Johnson, former deputy commissioner of the state Department of Mines and Minerals. The attorneys tried to walk into the interviews, but were turned away.

On Tuesday, the families were told that they could submit written questions before the hearing to be asked during the interviews. But the widows said Wednesday that they were not mining experts and that their representatives should be allowed to observe the proceeding and ask questions as they arise.

The Darby mine has been closed since the explosion. Preliminary reports showed that three miners died from carbon monoxide poisoning, while the other two were killed by the heat and explosion.