A soldier with the 101st Airborne Division was killed during a nighttime live-fire exercise at Fort Campbell early Wednesday, the Army said.

The soldier was hit by small arms fire and taken to Blanchfield Army Community Hospital, where he died of his wounds around 4 a.m., Fort Campbell said.

The soldier's name was not immediately released. He was assigned to the 1st Brigade Combat Team at the sprawling Army post on the Kentucky-Tennessee border.

Nighttime drills with live ammunition give soldiers better familiarity with their weapons in dark conditions, said Kelly Tyler, a spokeswoman at the Army post.

"They're called to go on patrols at all hours, so they need to be familiar with their equipment and operating in low-light situations," she said. Soldiers performing the drills are required to wear Kevlar vests and helmets, Tyler said.

She didn't know what kinds of weapons injured the soldier or the circumstances.

The death is under investigation by military officials.

The last Fort Campbell soldier to be similarly killed during a training exercise was in July 2005, when Pfc. Gregory B. Wertz, 19, was shot while training on how to clear buildings of enemy insurgents.