Investigators could go to work today on trying to find what caused a deadly explosion in an eastern Kentucky coal mine over the weekend.
The underground mine in Harlan County was having its ventilation system repaired so that it would be safe for investigators to enter.
Officials had been concerned about remaining pockets of methane gas.
The explosion at Darby Mine Number One in Holmes Mill killed five miners early Saturday.
A preliminary autopsy report released yesterday shows that three of the five miners died from carbon monoxide poisoning after the blast.
The coroner says two other miners died of blunt trauma and fire injuries.
Harlan County Coroner Philip Bianchi says officials might be able to determine how long the three miners lived, but that would depend on their toxicology reports.