Rain, specfically flooding.
The PGA Tour released a statement regarding this:
"Given the rain that the golf course received, the maintenance team and the golf course itself responded remarkably. After spending the morning repairing bunkers and working tirelessly to get the course in appropriate condition, Rules and Competition staff have assessed the playability of 18 holes and have determined that due to the excessive amount of rain the par-4 10th will be significantly shortened for round 2. Preferred lies will be in effect for the second round. Should all players finish the second round on Saturday, the third round will begin Sunday morning at 6:30 a.m. local time."
The hole was shortened to 140-yards and par was unable to be changed to reflect this change.