An 18-year-old gunman opened fire at a Texas elementary school, killing at least 19 children as he went from classroom to classroom, in the nation's deadliest school shooting in nearly a decade.

An 18-year-old man shot his own grandmother before storming into a West Texas elementary school and opening fire Tuesday morning, just two days shy of the end of the school year. During the rampage, 14 students and one teacher were killed, Texas Governor Greg Abbott said.