A gunman opened fire on Fort Hood in Texas this afternoon, killing at least one person. According to authorities, the man is still at large.

Multiple injuries have already been reported and at least one person was transported to a hospital. A witness told News 10 the man fired around 20 rounds into a post motor pool, injuring three people.

The army base in currently on lockdown.

This is the second mass shooting at Fort Hood in five years—in 2009, Nidal Malik Hassan shot and killed 13 people, injuring 30 others.

UPDATE 6:22 PM: A Fort Hood spokesperson tells KWTX that at least one person has died in the shooting.

7:40 PM: The AP reports the gunman was one fatality.

7:55 PM: President Obama just addressed the shooting, saying, "We're heartbroken something like this might have happened again."

8:57 PM: NBC reports four fatalities—the gunman and three of his victims. Another victim is in grave condition, and another 11 are injured.

The shooter has been identified by multiple outlets as 34-year-old enlisted Army soldier Ivan Lopez, who NBC says was in uniform during the attack. According to the network, "the shooting may have resulted from an argument in the motor pool."

[image via AP]