Authorities were searching floodwaters for two 18-year-olds from the central Illinois community of Taylorville.
Police say the two were last seen Monday and divers concentrated their search Wednesday near flooded areas of Sangchris Lake and Pawnee, where one of the teen's cellphone was tracked.
Christian County emergency services director Mike Crews told the State Journal-Register that ``it's going to be difficult to find them'' because the water is so high and that authorities may have to wait for it to recede.
Seven people have died in Illinois flooding since last week.
Gov. Bruce Rauner declared five more counties disaster areas on Wednesday for a total of 12. Christian County is among them.
Rauner is scheduled to return to Springfield on Thursday evening and planned to survey flood damage.