Forty Ranger students and four Ranger instructors were taken to the hospital Wednesday after they were hit by lightning during training. The students were learning lightning protection protocols at the time of the incident.
All 44 of them had returned to duty by Thursday evening, officials said.
The Army initially reported nine students and two instructors remained hospitalized Thursday afternoon for observation. Their injuries were not life-threatening.
The lightning hit at 4:55 p.m. Central time Wednesday at Eglin Air Force Base, Florida. The students were two-thirds of the way through Ranger School's Swamp Phase.
A total of 44 people — 40 students and four instructors — were taken to a local hospital, officials said.
The course's two female students, who are part of the Army's gender-integrated assessment of the grueling two-month school, were not involved, officials said.
Of the 44 soldiers, 17 students and three instructors remained overnight in the hospital.
The remaining soldiers were treated and released.
"The Ranger students and instructors reacted and got everyone proper medical care quickly," said Col. David Fivecoat, commander of the Airborne and Ranger Training Brigade, in a statement. "Ranger students and instructors are tough. [The] students will return to training tonight and continue with increased medical monitoring as they try to earn their Ranger tab."
Ranger School's Swamp Phase is conducted at Camp Rudder on Eglin Air Force Base. It is the third and final phase of the school, and it focuses on the continued development of the students' leadership and small-unit tactics.
During the 17-day Swamp Phase, students learn waterborne operations, small boat movements and stream crossings. They also will be required to execute extended platoon-level operations in a coastal swamp environment.
Ranger students who successfully complete this phase will graduate from Ranger School and earn the coveted Ranger tab.
Michelle Tan is the editor of Army Times and Air Force Times. She has covered the military for Military Times since 2005, and has embedded with U.S. troops in Iraq, Afghanistan, Kuwait, Haiti, Gabon and the Horn of Africa.