Update: The company cited for three deaths in a Gibson County mine last summer is responding to the report released Monday from the Mine Safety and Health Administration. In a statement to FOX 7, Frontier Kemper says they are disappointed in the citations handed down by MSHA. The company says it was in compliance with all standards, regulations and procedures, adding their work had already been observed and approved by MSHA at the time of the accident. The company says it plans to fight the findings. Three Frontier Kemper employees died August 10th when the sinking bucket they were standing in tipped over and they fell 500 feet to their deaths. The company was building a new airshaft at the Gibson Coal Company. The MSHA investigation report says the contractor was at fault for the deaths. Monday: An investigation into what caused a Gibson county mine accident shows the company Frontier Kemper is at fault. The private contractor was giving tours of their new mine shaft the day three people fell to their deaths. It should have been a day of celebration for Frontier Kemper. The independent contractor was celebrating 100 years as a construction company on August 10th 2007. But it turned into a day of mourning and an investigation shows the company was at fault. Three of their workers, including two visiting for the companys birthday, fell 550 feet down a mine shaft to their deaths. 38 year old Todd Richardson was in from Virginia. The mining operations manager with 15 years experience wanted to get a closer look at the work along with 66 year old retired Senior Executive Vice President and Director of the company Dan McFadden who came from Wyoming to the Princeton site. Their escort was 23 year old Jared Ashmore, a project manager from Slaughters Kentucky. An investigation shows the bucket three were standing in to get to the bottom of the mine tipped over and the three fell out. MSHA says it tipped because a 20 foot nylon sling connected to the nylon bucket should have been taken off. That sling then got wedged in a door at the top of the shaft causing the bucket to tip and dump the men out. The reports say Frontier Kemper should have had someone watching the bucket as it went down, but no one was in a spot to keep their eye on it. MSHA also says the workers should have been strapped in with fall protection. Its a safety restraint ensures all workers stay connected to the sinking bucket. To ensure this doesnt happen again MSHA says the company cannot transport people with anything attached to the bucket. Someone must also always watch the sinking bucket while its moving down the mine shaft and all employees are required to wear fall protection.