Two fourth-graders in a northern Minnesota county jumped in to save the day when their bus driver suffered a medical emergency while driving them home from school.

Lucy Marshall sensed something was not right when the school bus taking students home Tuesday afternoon from Riverside Elementary in Brainerd didn't make one of its scheduled stops.

Marshall spoke to the 74-year-old driver about the missed stop, but he didn't respond. The driver, it turned out, had suffered a medical emergency, Brainerd School District Superintendent Peter Grant said.

"She knew something was wrong," Grant said in an interview Wednesday. "She grabbed the [bus] radio and called for help."

The bus was supposed to stop at a transfer point where students from several schools meet to board other buses to continue their trips home.

Marshall's bus with 30 students on board didn't go to the stop. She told dispatch about the trouble, Grant said.

The driver, identified as Peter Lodermeier, didn't know where he was, Grant said. Neither did Marshall. But the girl did see a sign that said 45, which turned out to be County Road 45, and another sign that said 100. From that, dispatchers were able to figure out about where the bus was and send help, Grant said.

Another vehicle might have helped get the bus stopped. Once that happened, Marshall and another fourth-grader, Kabe Storey, took charge. The two ushered the remaining students off the bus in single file and had them stand on the side of the road, Grant said.

"They made great decisions," Grant said, noting students had practiced bus emergencies in the past. "These two kids helped kids get off the bus safe and sound."

Students were released to their parents at the scene. Those who were not picked up were taken home on another bus, the Crow Wing County Sheriff's Office said.

Lodermeier was taken to a hospital and was last listed in serious condition, the sheriff's office said.

As for the brave fourth-graders, "never underestimate how smart kids are," said Grant, who met with the do-gooders Wednesday morning. "We are very fortunate. This could have been a bad state of affairs."