Updated on Thursday, March 29: Core services are back online.
The city of Denver's website was offline for hours on Wednesday, as were numerous government computer and phone systems, including the text-to-911 system.
The city's website, email, 311 and other core services were restored by Thursday morning, and there was no sign of malicious activity, according to city representatives.
City technicians have confirmed that a software bug impacted network equipment, according to spokeswoman Amber Miller.
However, at least one minor service, an interactive zoning map, remained inoperable.
The city first announced the outage via Twitter just after noon on Wednesday. Denver's 311 information service also went down and city staff lost access to email and to digital systems for permits and other services.
The crash affected the text-to-911 system, which allows users to request emergency assistance via text message. The regular 911 phone system remained active, according to police.
In Atlanta, attackers disabled numerous city services and demanded a ransom in an attack that has lasted nearly a week. But there was no sign that Denver is the victim of malicious activity, according to Miller.
"We have no reason to believe that the network outages are being caused by a cyber attack and city data has not been compromised," she wrote in a text message on Wednesday afternoon.
Technical staff later confirmed that it was "a software bug that impacted our network equipment. No cyber attack. Confirmed," she wrote in a text on Thursday morning.
The city has experienced similar outages in the past, including the short outage on Tuesday, according to Miller.
