Sergeant Jeremy McQueary died two months before he was scheduled to come home to his wife and infant son.
The explosion is the third in a series of four demolitions that will lead to the removal of the entire old Milton-Madison Bridge.
The 10-year nesting site will remain undisturbed during construction, officials say.
The bridge, which crosses the Eel River between Spencer and Terre Haute, has been closed since July.
The lights were turned off eight years ago because of vandalism.
The over $2 billion project will relieve traffic congestion for Louisville and southern Indiana.
The bridge, although it’s likely still many years from completion, is a joint project between the two states.
The Sherman Minton Bridge had been closed for repairs since September.
The Sherman Minton Bridge could be completed a week earlier than expected.
City and county infrastructure is much worse than state-run roads, according to Indiana engineers.