MADISON (WKOW) -- The Madison Metropolitan School District (MMSD) received fake threatening calls on Tuesday morning, the day after a deadly shooting at private school also in Madison.

In an email sent to the MMSD community, the district reported that calls were made to several schools saying that someone in crisis was outside of the building with a weapon. The calls appeared to come via 988, the Suicide and Crisis Lifeline.

The district contacted the Madison Police Department right away, and officers quickly found there was no credible threat.

In the email, the district acknowledged these hoax calls, also known as "swatting," are common, particularly following tragedies. MMSD said it treats every threat with "the utmost seriousness and conducts thorough investigations in partnership with law enforcement."

A teacher and student were killed in Monday's shooting at Abundant Life Christian School. The suspected shooter, a 15-year-old female student, died of an apparent self-inflicted gunshot wound.