Why are they scarce? Sounds like plenty of witnesses are available such as lifeguards, coaches and swimmers.
From The Baltimore Sun:
That night, city fire spokesman Chief Kevin Cartwright said emergency personnel responded to a call at the pool about 10 a.m. Sunday, and found a lifeguard administering CPR to Louis on the pool deck.
Cartwright said paramedics performed "advanced life support measures" en route to the hospital.
Just before 10:15 p.m. Sunday, as word of the incident began to spread and false reports regarding Louis' condition began surfacing on social media, NBAC Director of Operations John Cadigan sent an email to club member families updating them on the situation.