The shooting at a Florida high school was the 18th of its kind this year in the United States.
At least 17 people were killed and another 14 injured when a gunman opened fire at Marjory Stoneman Douglas High School in Parkland.
Nikolas Cruz, a 19-year-old former student who was expelled, has been arrested in connection with the shooting.
It is not an isolated incident and takes the total to 18 shootings at schools in the 44 days of 2018.
Texas has already seen three separate shootings take place in its schools since the turn of the year, while California and Michigan have both had two incidents.
The 18 school shootings since 2018 began
January 3: At the start of the year a 31-year-old man shot and killed himself at a school in Michigan.
January 4: A bullet went through a window at New Start High School in Washington state but nobody was hurt.
January 10: A student committed suicide at Coronado Elementary School in Arizona and was found with a self-inflicted gunshot wound.
January 10: A shot was fired at a window at California State University but no one was struck by the bullet.
January 10: A bullet was fired through a wall at the Grayson College Criminal Justice Centre in Texas, but no one was injured.
January 15: At Wiley College Campus a bullet went into a dorm room but no injuries were reported.
January 20: Najee Ali Baker, a student at Wake Forest University, was mortally wounded after being shot following a fight on campus.
January 22: A 16-year-old targeted a girl a year younger in the cafeteria of Italy High School, Texas. The victim was injured but survived the incident.
January 22: A 14-year-old boy suffered a flesh wound in the parking lot of a New Orleans high school.
January 23: Two people were killed and 14 injured at a Kentucky school. Bailey Nicole Holt and Preston Ryan Cope were fatally injured during the shooting for which a 15-year-old student was arrested for.
January 25: A student at Murphy High School in Alabama opened fire on the school's grounds but did not injure anyone.
January 26: Gunshots were fired from a car in the Dearborn High School car park in Michigan.
January 31: A fight at Lincoln High School resulted in a 32-year-old father of eight being shot dead. Three separate weapons were used in the incident.
February 1: A 12-year-old girl was arrested after taking a loaded gun into Salvador B. Castro Middle School in California. The gun went off accidentally, shooting a 15-year-old boy in the head and a girl of the same age in the wrist but both are expected to recover from their injuries.
February 5: Two teenagers were charged with attempted murder after a 17-year-old was shot twice in the chest while in a car on the Oxon Hill High School grounds.
February 5: During a school event at the Harmony Learning Centre a child reach into a police officer's holster and pulled the trigger on his gun. No one was hurt.
February 8: No one was injured when a teenager fired a shot at the Metropolitan High School in New York.
February 14: At least 17 people died when a gunman opened fire with an assault rifle at the Parkland school in Florida.