Rise event in main class when aggregated classes perform an action

I have 3 classes. I use aggregation to extend main class. How I can rise events from main class, when I perform operation in UnitHealth and UnitSkill classes?

I can duplicate event in aggregated class (UnitHealth, UnitySkills), and subscribe on it from Unit (main class). But it seems to me that it is bad idea.

public class Unit
{
  public static event EventHandler HealthChanged;
  public static event EventHandler SkillUsed;

  private UnitHealth health;
  private UnitSkill skill;
}

public class UnitHealth
{
  void ChageHealh()
  {
  }

}

public classUnitSkill
{
  void UseSkill()
  {
  }
}