Yale spokesman Thomas Conroy told local newspaper the New Haven Register, “Everyone is following instructions they were given in these alerts".
The Yale alerts warning an emergency situation is in place are sent by email, text message and phone.
Everyone in our community receives these alerts ... Everyone is alerted in multiple ways,” he added.
Students at Yale University have been on break since Saturday and classes do not resume until 2nd December.
More top news
An undercover investigation claims England manager Sam Allardyce offered advice on how to "get around" FA rules on player transfers.
The four artworks shortlisted for this year's Turner Prize include a huge golden sculpture of buttocks, and more than £20,000 in pennies.
A proposal to sell ivory stockpiles and return profits to communities that sustain elephants has been defeated at a major global conference.