April 20, 1999
(KGTV) - The school shooting in Parkland, Florida, was the third deadliest in U.S. history.
The number of victims was lower than at Virginia Tech or Sandy Hook.
Tragedies like these have been escalating since 1999.
RELATED: Remembering the 2001 San Diego school shootings
See a timeline of the deadliest school shootings: