Georgia Insurance and Safety Fire Commissioner Ralph Hudgens tells WSB-TV that maintenance workers at Finch Elementary School had started taking it apart by the time investigators from his office arrived.
Hudgens said that "destroyed any ability that we would have to determine what the cause was."
Atlanta Public Schools spokesman Steve Alford tells The Associated Press that maintenance workers were trying to resolve an emergency issue. He said their primary concern was to identify the issue and make sure students were safe.
More than 40 students were treated at hospitals Monday after the leak.