Two sons he coached at Carmel were named Mr. Basketball recipients: Billy in 1968 and Dave in 1970.
The superintendent of Carmel Clay Schools sent a message on Monday.
The explosion occurred about 6:10 p.m. Wednesday on the second floor of the building housing the gymnasium and swimming pool.
The department said on Twitter that the explosion occurred on the northwest corner of the high school.
One Hoosier is among 312 in the qualifying pool for the prestigious U.S. Amateur from Aug. 13-19 at Pebble Beach Golf Links and Spyglass Hill Golf Course in California.
The game is hosted by the Colts' mascot Blue and it pits NFL mascots against pee wee football players.
If convicted, the man could face at least 15 years in prison.
Authorities say he had a sexual relationship with a female athlete he coached.
Carmel Clay School officials announced the selection of a new superintendent Friday amid unrest in Hamilton County and the state over student safety.
In Carmel, Mayor Jim Brainard declared Thursday to be Christopher "Tripp" Zanetis Day.