A. if you mean that your plants wilt and turn yellow:
squash vine borer- you will notice frass (insect poop that looks like wet sawdust) at wounds on lower stems or the base of the plant. Cut halfway through the stem just above or below the wound to search for the cream color larvae with brown head:
2. bacterial wilt disease- spread by cucumber beetle feeding. No cure; plants should be removed:
It's not too late to plant a late summer squash crop.
B. if you mean that fruits drop off the plant when they reach 2 inches in length (not 2 ft. in length). There are two primary possibilities:
1. poor pollination due to low pollinator activity (not enough bee visits) or environmental conditions that damaged flower parts
2. choanephora rot- a fungal disease that moves from flower to fruit while the flowers and baby fruits are still attached to each other. The fruit end will get fuzzy, and turn black/gray/brown in color. Flowers get mushy and rot. If his is the case, remove flowers from fruits when the baby fruit begins to enlarge (flower has been properly pollinated and the ovules (undeveloped seeds in baby fruit) are fertilized.
Be patient- more squash are coming. Let us know if symptoms worsen.