A mother is crediting the brightly colored soles of her son's shoes with giving the 5-year-old boy a chance at surviving after being stuck for up to 13 minutes under his family's boat. The boat was struck by a barge over the weekend on the Mississippi near Red Wing.

Vincent Koenig was in critical condition Monday afternoon at Mayo Clinic Hospital, St. Marys campus in Rochester, a hospital spokeswoman said, following the crash about 5:45 p.m. Friday near the Ole Miss Marina gas dock that also sent his father and three siblings into the river.

The boy's mother, Rachel Koenig, elaborated on a CaringBridge web page late Monday afternoon that "Vincent's brain scans are normal! … This is the best news we could have asked for, and his [medical] team was so excited to tell us!"

Rachel Koenig's positive prognosis came a day after other positive indicators. She said that "Vincent was attempting to move all extremities, squirm in the bed and grab at his endotracheal tube. He was very clearly wanting this out and was coughing to help bring secretions out of his lungs. … He purposefully kicked his right leg while neurology physicians were in the room."

In its latest and most detailed account yet Monday of the crash, the Goodhue County Sheriff's Office said 45-year-old Jeremy Koenig and three of his children were pulled from the water by other boaters nearby. However, Vincent remained missing.

It was only after the disabled boat was towed by another vessel to the nearby Red Wing Marina that the boy "was found under the boat [and] lifted to the dock, where CPR was started," a Sheriff's Office statement read.

Vincent apparently had been under the water for about 12 to 13 minutes, Sheriff's Office spokeswoman Kris Weiss said Monday.

Dr. Ashley Bjorklund, an HCMC pediatric intensive care doctor, said that "time alone does not give him a prognosis" for survival or being spared serious injury.

"We always give kids a fighting chance when we can," said Bjorklund, who emphasized that preventive steps such as wearing a life jacket — as all four children were — and supervising children are vital to prevent life-threatening incidents on the water. "Young brains do much better and can overcome things that an older brain can't do."

Vincent's siblings were identified by the Sheriff's Office as Jack, 11; Felix, 8, and Hazel, 3.

"Jeremy and I along with our family are living a parent's worst nightmare," read Rachel Koenig's initial posting on CaringBridge.

She said her husband and children were out fishing when the boat stalled, and it was hit by an oncoming barge.

The boat capsized, and "Vincent was stuck underneath," the mother continued.

"Thank goodness he was wearing shoes with orange bottoms," Rachel Koenig noted. "Jeremy spotted his shoes and was able to find him."

Vincent was lifted to the dock, where cardiopulmonary resuscitation was started, the Sheriff's Office said.

"I'm told that all the bystanders were extremely wonderful, and they began CPR until EMS arrived," Rachel Koenig wrote. From there, he was taken by air ambulance to Mayo in Rochester.

"Kudos to the Red Wing boating community for their response," Weiss of the Sheriff's Office said.

Rachel Koenig said brother Felix visited Vincent on Saturday, and Jack followed on Sunday.

"They brought Vincent his favorite coloring books and Teddy bear from home," she wrote on CaringBridge. "They are both very brave to see their brother in this condition."