TALLMANSVILLE, W.Va. - Some of the 12 coal miners who died following an explosion left notes behind assuring family members that their final hours trapped underground were not spent in agony, a relative said Thursday. "The notes said they weren't suffering, they were just going to sleep," said Peggy Cohen, who had been called to a makeshift morgue at a school to identify the body of her father, 59-year-old mining machine operator Fred Ware Jr. Cohen said a note was not left with Ware's body, but that she planned to retrieve his personal belongings later Thursday to see if he left one in his lunch box. But she said the medical examiner told her notes left with several of the bodies all carried a similar message: "Your dad didn't suffer." Ware was among a dozen miners who were found after 41 hours inside the mine. They were found at the deepest point of the Sago Mine, about 2 1/2 miles from the entrance, behind a fibrous plastic cloth stretched across an area about 20 feet wide to keep out deadly carbon monoxide gas. Cohen said her father had the peaceful look of someone who died from carbon monoxide, and the only mark on his body was a bruise on his chest. "It comforts me to know he didn't suffer and he wasn't bruised or crushed. I didn't need a note. I think I needed to visualize and see him." The sole survivor, 26-year-old Randal McCloy, remained in critical condition in a coma in a Morgantown hospital Thursday with a collapsed lung, dehydration and other problems. A spokeswoman for Gov. Joe Manchin said autopsies on the dead should be completed either late Thursday or early Friday, and his office indicated that if the families want him there, he would attend all the funerals. Families of the victims are considering legal action, said Amber Helms, whose father, fire boss Terry Helms, was among those killed. "It's the biggest thing that's going to happen after these miners are put to rest," she said Thursday on NBC's "Today." In other developments, federal and state investigators were at the mine Thursday seeking a cause for Monday's explosion. Coal mine explosions are typically caused by buildups of naturally occurring methane gas or highly combustible coal dust in the air, but what exactly triggered that explosion remained unclear. The Charleston (W.Va.) Gazette reported Thursday that a federal contractor that monitors thunderstorms detected three lightning strikes within five miles of the Sago mine within a half hour of Monday's explosions. The contractor, Vaisala Inc., said two of the strikes, including one that was four to 10 times stronger than average, hit within 1 1/2 miles of the mine. David Dye, who heads the federal Mine Safety and Health Administration, said that in addition to the cause, investigation will also probe "how emergency information was relayed about the trapped miners' conditions." Just before midnight Tuesday, families received word that 12 miners were alive. Bells at the church pealed and politicians proclaimed the rescue a miracle before the truth emerged three hours later. At that point, the families' joy turned instantly to fury, with one man lunging at coal company officials. Ben Hatfield, chief executive of mine owner International Coal Group Inc., said that the Ashland, Ky.-based company did the best it could under extreme stress and exhaustion, and that officials "sincerely regret" the families were left to believe for so long that their loved ones were alive. "In the process of being cautious, we allowed the jubilation to go on longer than it should have," a choked-up Hatfield said. He said the initial mistake resulted from a miscommunication among the rescue crews. Another ICG executive, vice president Gene Kitts, suggested the misunderstanding resulted because the rescuers who reached the victims were wearing full-face oxygen masks and used radios to report their findings to their base. One of the dead was discovered several hundred feet from where the others had barricaded themselves in the maze-like mine. Hatfield said that miner, found near a belt used to move coal to the surface, was apparently killed by the force of the blast. As for the other group of a dozen miners, ICG's Kitts said the rescuers realized McCloy was alive when they heard him moan, and he may have been the farthest away from the bad air. Doctors said McCloy's youth may also have helped him survive; most of the other miners were in their 50s. A fund to provide financial support to the miners' families has been established by ICG with an initial contribution of $2 million, company Chairman Wilbur L. Ross said Wednesday. "No amount of money can take the place of a loved one," he said in a statement, "but the families do have financial needs as well." The explosion was West Virginia's deadliest coal mining accident since 1968, when 78 men died in an explosion at a mine in Marion County, an hour's drive from here. That disaster prompted Congress to pass the Mine Health and Safety Act of 1969. Sago was the nation's worst coal mining disaster since a pair of explosions tore through a mine in Brookwood, Ala., on Sept. 23, 2001, killing 13. At a vigil attended by about 200 people in Sago on Wednesday night, the Rev. Wease Day said the days ahead will bring funerals and mourning for the victims, but insisted they must also include a celebration of the lives that were lost. He spoke specifically of Ware, a fellow parishioner who lived across the road from the church and was so good-natured he didn't mind being awakened to be asked to help with sanctuary repairs. "We need to be sad. We need to pray for the families," Day said, "but we also need to be joyous."