Hobbs Kessler ran 3:57.66 broke Drew Hunter's indoor HS record by .04.

[CC Track Fan]

Kid is from Michigan. Of note Nick Willis his training partner broke 4:00 again. This is his impressive 19th straight year sub 4:00. He was breaking 4:00 before this kid was even born.

Results

 

[JAVMAN83]

The differential was 0.15 seconds, not 0.04 seconds. Drew Hunter, the previous record-holder, ran 3:57.81 back in '16.