The university took some computer systems offline after reporting a network disruption but has not confirmed the cause or disclosed a recovery timeline.
Officials said the attempt was detected quickly and did not jeopardize water or wastewater systems; federal agencies warned of incidents in at least seven states.
Email, internet access, Google Drive and other applications were unavailable as forensic specialists investigated days before registration and the start of classes.
The city said water remained safe as crews used manual procedures after communications failed at two water towers and multiple wastewater lift stations.
The district is investigating unauthorized network activity days before schools open Aug. 3, with affected services and possible data exposure still unclear.
Emergency departments remained open as phone and internet outages forced outpatient closures, limited infusion services and led to reported patient diversions.
Northwest Iowa Community College canceled on-campus classes and restored systems before disclosing more than seven months later that investigators found unauthorized activity during the disruption.
A 15-hour outage affected three public websites, but 911, 311, bill payments and permit services remained available, and officials reported no intrusion or data loss.
