Jessie Contreraz, uncle of a 2-year-old toddler who was swept away by floodwaters Monday night near Rude Park in Denver, searches the riverbank for his nephew's body along the South Platte River on Tuesday morning. The storm also swept away a teenager who was trying to help with a rescue. Both were still missing Tuesday and were presumed dead, police said.

Denver ? Divers searched the South Platte River on Tuesday for a 2-year-old boy swept away in his stroller and a young man who disappeared in flash flooding during a sudden thunderstorm. Both were presumed dead, authorities said.

The boy’s mother had been out for a stroll with her son Monday evening along a bike path that follows the river downtown. A thunderstorm developed quickly, dumping more than an inch of rain and sending a torrent of water down the river.

The mother put the toddler in his stroller to protect him from hail, but torrential rain pushed the stream over its banks. The flood knocked the woman down and tore the stroller, with the boy inside, from her hands, Fire Department spokesman Phil Champagne said.

The mother, found clinging to a concrete barrier in the fast-running water, released her grip and slipped away from a rescuer when she was told her son had not been found, Champagne said. She was pulled from the river about 100 yards downstream and hospitalized.

“She … looked at the rescuer and let go of the concrete (barrier) and said she no longer wanted to live without her child,” Champagne said.

Family members identified the toddler as Jose Matthew Jauregui Jr. The mother, identified as Elsha Guel, was released from the hospital, relatives said.

Firefighters on Tuesday found a stroller 1 1/2 miles downstream, but Champagne said it wasn’t yet known if it was Jose’s.

About eight miles away, a police officer jumped into a swollen creek to try to rescue a teenager or young man but could not reach him, fire spokeswoman Heather Green said. The missing person had yet to be identified Tuesday, authorities said.

Water still overflowed part of the path alongside the South Platte as about a dozen rescuers, using metal probes, searched for the missing. Firefighters estimated the water had crested 4 feet higher along the river Monday night.