How to handle death of company co-founder

HR department of one checking in. The company is <100 people and about 10 years old. One of our founders retired last year and just passed away over the weekend. I have no idea how to handle it.

My gut says to send an email to everyone (obviously being very respectful and heartfelt) but the current CEO wants to put an all-hands call on the calendar for tomorrow morning to tell everyone.

Has anyone been through something similar? I’ve never had to draft a death announcement before.