By Sam Schechner and Sarah E. Needleman

More than a dozen Google services such as Gmail and YouTube were offline for roughly an hour Monday, long enough to close schools, disrupt work and highlight again our dependency on the internet amid the coronavirus pandemic.

The Alphabet Inc.-owned company's services showed errors for users attempting to sign in or access their email or files, according to social media postings from users. On YouTube, the home page was replaced with an illustration of a monkey with a hammer with the title, "oops."

On Google, searches for "Is Google down?" rocketed in popularity.

A Google spokeswoman said Monday that the outage affected the company's system that authenticates login credentials for users of its wide array of services. Engineers traced the problem to internal servers and the issues weren't the result of a cyberattack or recently announced changes to cloud-storage quotas within certain Google products, the spokeswoman said.

The outage began about 6:45 a.m. Eastern Time and lasted roughly an hour, the company said. Google apologized to affected users and in a statement pledged to "conduct a thorough follow up review to ensure this problem cannot recur in the future."

The problems affected services used by billions of people world-wide, which are being relied upon more than ever as people have stayed home on and off for the better part of a year because of the coronavirus pandemic. Remote work and learning have left businesses and individuals more dependent than ever on online services, for which Google is widely used.

Google's Gmail is one of the most popular email clients globally, and the company's Workspace office tools, formerly known as G Suite and a competitor to Microsoft Corp.'s Office, are popular among businesses and institutions.

"Why g suite why? Why would you crash on a freakin Monday!! Oh wait #2020," wrote one Twitter user.

At The Wall Street Journal, where the newsroom uses Google's services, a reporter had to use an older form of technology -- the telephone -- to dictate the first paragraphs of a story on the outage.

Some schools closed for the day. Wayne-Westland Community Schools in Westland, Mich., gave its roughly 9,800 elementary, middle- and high-school students the day off after a morning of disruption. They rely on Google for classes over Google Meet and for exchanging emails.

"We already lost our window for the beginning of the school day," said Jenny Johnson, a spokeswoman for the 19-school district, which earlier this year provided its students with Chromebooks and internet hot spots. "This is the new snow day."

Ms. Johnson said she doesn't expect the district to switch to an alternative service at this time, but it is a possibility in the future. "Until today the Google platform had worked great for us," she said. "Our tech department is always looking for what is the best for our kids so they'll come up with recommendations."

The outage inspired Indira Saladi to rethink her physician-staffing business's disaster plan. "I'm very dependent on Google," she said. "Most disaster plans are for in case phone networks go down, so I need a multi-tier disaster approach." Her company, Orchard Inc., is located in a Chicago suburb but does business nationwide and relies on Google's cloud-based applications including Gmail, Sheets and Drive to reach contract workers, physicians and customers. "We no longer keep things on our computers locally," Ms. Saladi said.

"I was worried about my physicians being at the hospitals they needed to be at" she said, especially given the high demand created by Covid-19. "I couldn't check their schedules."

Temporary interruptions to the availability of popular online services are relatively common occurrences, though their impact has increased as more businesses outsource their digital infrastructure and tools to outside businesses, often large internet companies. A decade ago, a Twitter Inc. outage -- accompanied by an error image dubbed the "fail whale" -- might have boosted office productivity. Today, outages can slow some companies to a crawl.

In November, Amazon.com Inc. grappled with an hourslong outage tied to its enormous cloud-computing operation that affected operations of many of its clients, such as video-streaming device company Roku Inc. In July, apps such as Spotify and Tinder experienced outages for several hours because of what Facebook Inc. said was a bug in its software for iPhone users.

In March 2019, some Google services including Gmail were slowed or inaccessible because of what the company called a "cascading failure" that began after its engineers made tweaks to an internal storage service. The same week, services from Apple Inc. and Facebook also suffered outages.

Monday's Google outage almost cost poet Nic Tregenza-May of Devon, England, around $6,500. He was supposed to record himself doing a spoken-word performance for a holiday themed TV commercial. The company that had hired him for the gig offered to buy the rights to his work and instructed him to store the poem he wrote in a Google doc. "Today was the final day I could do my bit," he said. Once the outage lifted, he had about two hours left to get the job done, and he said he expected to meet that deadline.

Write to Sam Schechner at sam.schechner@wsj.com and Sarah E. Needleman at sarah.needleman@wsj.com

(END) Dow Jones Newswires

12-14-20 1837ET