Online collaboration service Slack suffered a major outage on Monday as people tried to get back to business remotely on the first work week of the new year.

San Francisco-based Slack put out word early Monday that people were having trouble connecting to the service, then upgraded the incident to an outage a short time later.

"We apologize for any disruption caused," Slack said in a message at its status board.

"All hands are on deck on our end to further investigate."

The problem remained "largely ongoing" into late morning in California, with Slack recommending customers refresh connections in the off-chance that helps.

Use of online collaboration services operated by Slack, Zoom, Google, Microsoft and others has soared as the pandemic fuels a remote work trend.

Salesforce early last month announced a $27.7 billion deal to buy Slack, giving the business software giant a broader array of tools.

San Francisco-based Salesforce planned to mesh Slack messaging technology with its platform for managing marketing and sales teams.

The deal is expected to close this year pending shareholder and regulatory approval.

A core reason for the acquisition is to keep pace with "cloud behemoth" Microsoft and its popular productivity tools.

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