The kids were involved in a car accident Sunday while their father was on the red carpet at the BET Awards. Mayweather was on the phone with Bieber while attending the awards ceremony and told him he felt bad he wasn't there for his children.
Bieber happened to be driving near where the accident occurred so he rushed to the scene to check on the younger Mayweathers.
Sources told TMZ the children weren't seriously injured. One of the children had a busted lip.
Law enforcement allowed Bieber to drive the kids to their father after which he returned to the scene to let police know they were safe with the boxer.