In Snyder v. Curran Township, 167 Ill. 2d 466, 657 N.E.2d 988, 212 Ill. Dec. 643 (1995), the supreme court stated that it is the long-standing common-law principle that,"although a governmental agency has discretion in determining whether to perform a public work or make an improvement, once the decision to perform the work is made, it must be done with reasonable care and in a nonnegligent manner." Snyder, 167 Ill. 2d at 474-75, 657 N.E.2d at 993.