BRANTFORD, Ont. – Torrential rains and mild temperatures pushed the Grand River in southern Ontario to breach its banks Wednesday, forcing thousands of people from their homes and touching off a search for a missing toddler.Local officials near the town of Orangeville, Ont., were bracing for tragedy as they scoured the swollen river for a three-year-old boy who went missing after the car he was riding in got swept off a washed-out road.Ontario Provincial Police Const. Paul Nancekevell said the boy’s mother was driving near the river at about 1 a.m. on Wednesday when her vehicle plunged into the rapidly rising waters.“His mom got out of the car, she pulled him from the car, but she lost her grip on him and he was swept downriver,” Nancekevell said. “They were in the middle of fast flowing water.”Police are combing the area for the boy using helicopters, dive teams and ground search crews, he said, adding they are “keeping a good thought” about his ultimate safety.One other local official, however, said the effort was being viewed as a recovery operation rather than a rescue effort.Grand Valley District Fire Chief Kevin McNeilly said weather conditions were treacherous at the time the mother and son, believed to be from the area, went into the water. McNeilly, whose department was handling the search before police took over, said the crew was contending with dramatic spikes in the level of the river.“It was extremely foggy. Very, very violent river last night,” McNeilly said. “At one point it raised up three feet (about 90 centimetres) in a matter of 20 minutes.”The unexpected surges prompted a different kind of crisis nearly 100 kilometres away in Brantford, Ont., where officials declared a state of emergency due to flooding.About 4,900 people in roughly 2,200 homes are currently under an evacuation order covering neighbourhoods surrounding the river after the unseasonable conditions dislodged an ice jam near the city.Brantford Mayor Chris Friel said flooding has shuttered many local businesses and schools as well as closing city trails.Danielle Beaudoin, who lives less than a kilometre from the river’s shore, found out that she and her son would have to leave their home at about 9 a.m. Wednesday.“I had already taken him to school and I was getting ready for work myself when one of his older babysitters brought him back,” she said.After rounding up the family cats, Beaudoin hastily packed food, water and a change of clothes for her and her son before driving out of the evacuation zone. She said the river had risen so high that chunks of ice from the water surface were now resting on shore.The mayor urged all Brantford residents to steer clear of the river and surrounding areas for the foreseeable future.“It is never worth your personal safety for a view of the river … stay away from the river,” Friel said at a news conference. “That is not just for today or this afternoon or this evening. That will be for the next couple days at least.”Despite the warning, dozens of people still stood on the river’s banks Wednesday afternoon. They watched as the fast-moving waters brought chunks of ice, debris and fallen trees to a jam in the river.“I couldn’t believe what they were saying on the radio, that it was that bad,” said Gary Mills. “When I seen it, I said, ‘My God.’”The 67-year-old has spent his whole life in Brantford, but said he hasn’t seen the water rise this high since he was 12 years old.“They built the dike way down the other end to stop this from flooding, and it looks like it’s done its job,” he said. “It’s gone over in a few spots but not too bad.”Friel said the state of emergency went into effect mid-Wednesday morning. Local roads and bridges were jammed as people began to make their way out of the three neighbourhoods covered under the evacuation order, he said.Larry Davey, who was among those who flocked to the river, said he could feel the ice and debris hitting the bridge he was standing on, causing it to quake under his feet.Davey lives outside the evacuation zone, but said those who live within it have far more to worry about.“I spoke to a woman who lives in Eagle Place (one of the evacuated neighbourhoods) … and she had a foot of water in her living room, and the basement was entirely flooded,” he said.“The damage, once everything’s settled, that’s going to be scary.”Premier Kathleen Wynne told reporters Wednesday that the province would work with the city to determine what it could do to help, including looking at what infrastructure would need repairs.“I know there has been damage. We don’t know the extent of it at this point,” she said.“In these situations, everyone has to pull together. That is exactly what is happening here.”Officials at that news conference said that the city wasn’t yet out of the woods. A second surge was expected to hit the Grand River on Thursday morning, raising water levels yet again.“It’s a dynamic issue right now. We are unsure where we’ll end up,” Friel said.— With files from Michelle McQuigge and Peter Goffin in Toronto.