Kelsey Nobles, of Mobile, collapsed during training at the Navy Recruit Training Center in Great Lakes, Ill., on Tuesday, spokesman Lt. Joseph W. Pfaff said.
Nobles' father, Harold, told WKRG-TV that doctors said the woman went into cardiac arrest after a fitness test, and "couldn't be revived."
The recruit's death was the second at the Navy training center in just over eight weeks. On Feb. 22, Seaman Recruit Kierra Evans, 20, collapsed following the 1.5-mile run portion of the Navy's Physical Fitness Assessment. She was rushed to a nearby hospital but was pronounced dead several hours later, according to Military.com.
"For me, I'm just like, 'What's wrong?' These young people are so excited about serving their country and going into the military. Are they doing enough to check them? Does physical testing need to be more in-depth?" Harold Nobles told the news station.
Nobles was a kind person who "was just full of energy," her dad said. "She would give anyone anything, her last her dollar. She was the sweetest soul. That's the best way I can describe her."
Pfaff told Military.com that the Navy is investigating Nobles' death, as well as the way it runs boot camp.
"Recruit Training Command reviewed the training, safety, medical processes, and overall procedures regarding the implementation of the Physical Fitness Assessment and found no discrepancies in its execution," Pfaff told the outlet.
"However, there is a much more in-depth investigation going on and, if information is discovered during the course of the investigation revealing deficiencies in our processes and procedures that could improve safety in training, it would be acted on."
The Associated Press contributed to this report.