A car with a woman and her two small children inside veered into an east-central Minnesota lake after dark and was "completely submerged," sending the driver's 2-year-old son to a Twin Cities hospital with serious injuries, authorities said Monday.

The driver, Jessica L. Delcourt, 23, of Rush City, Minn., and her infant escaped from Mora Lake Sunday night unharmed, according to the State Patrol.

Taken to Children's Hospital in Minneapolis was Royce M. Rivera, the patrol added. A hospital spokeswoman said the boy was in serious condition Monday afternoon.

Delcourt was heading north on Hwy. 65 in Mora shortly after 10 p.m., when her car ran off the road to the right along a slight curve, the patrol said.

"The Saturn came to a stop completely submerged underwater," the patrol report read.

Paul Walsh • 612-673-4482