Just 1 negative item on your credit could lower your score by over 100 points in some cases. Here is a list for reference.
Credit Score Decrease by Item Type
Late Payment - up to 110 points
Debt Settlement - up to 125 points
Foreclosure - up to 160 points
Bankruptcy - up to 240 points
Collection - up to 110 points
Hard Inquiry - up to 15 points