State and local investigators are trying to find out more about how an Iowa Department of Transportation inspector died Monday at a Des Moines construction site along I-235. Construction continued today in the area where 55-year-old Bobby Lee Derrickson of Earlham was hit and killed by a loader. Just a few hundred yards away at the D-O-T’s main office for the I-235 reconstruction project, spokesperson Dena Gray-Fisher says they can’t say much about the details of what happened until the investigation is complete. She says they D-O-T in the meantime is doing all it can to assist in the investigation. Gray-Fisher says counselors have been talking with D-O-T workers and contractors on the project. She says it’s a very difficult time for the organizations as there’s a lot of shock among those who’re working on the project and those who’ve worked with Derrickson . Derrickson had been with the D-O-T for three years. He also was a snowplow operator in the winter and a member of the Earlham city council. Fisher says Derrickson’s death was the first at a construction site, since two D-O-T workers were killed in an accident near Hanlontown about two years ago. She says workers are given safety training, and understand the risks of working in construction areas. She says there’s a lot of heavy equipment involved and you’re working close proximity to the equipment, making it very dangerous. Gray-Fisher says the I-235 reconstruction is the largest single project in the history of the D-O-T.