Authorities are searching for a man at Kangaroo Creek, south of Grafton, less than a day after a toddler died at nearby Palmers Island.
Police were called to Kangaroo Creek Road at 10pm on Sunday after reports a four-wheel drive had crashed.
They arrived to find a white Toyota Landcruiser had slid down a steep embankment and stopped on the banks of a river.
Police said officers weren't able to reach the vehicle but did briefly see a man near the vehicle before he entered the river.
The 26-year-old man has not been seen since.
Police divers, a dog unit and aircraft have been called in to help find him.
The missing man's father Glen Barrett was celebrating his son and his son's step-daughter's birthday at the Coutts Tavern that evening.
"I'm not sure what time he's left the party and what's happened - just waiting to find out," he said.
Mr Barrett has been to the scene of the accident.
"I'd say he's done a tyre on his car - but how he didn't roll it ... I don't know how he kept it upright."
The father of two — a six-year old step-daughter and son who is almost two — and chef at a hotel in Grafton loved to camp and fish, said his dad.
"So he knows his way around the bush a little bit," he said.
"I don't know about roughing it overnight, out in the bush, not knowing the area, I don't know how he would go but he'd find some way of getting back."
Chief Inspector Joanne Reid said the search was challenging, with conditions in the flood-swollen creek difficult for boats.
"There's a lot of debris in the creek and, as you can imagine with the floods, it's sort of moderately flowing, so care needs to be taken there," he said.
"It's quite thick terrain down there, there's a fast flowing creek and darkness and rain through most of the night.
"This morning, it was raining for a period and there's lantana, debris and all sorts of obstacles that make it a challenging search."
A drone was put up last night and police were trying to cover as much ground from the air as they could, said Chief Inspector Reid.
'If you're not a local you'd miss it'
Kangaroo Creek resident Karl "Doc" Bolch said he heard the crash and initially thought it was a tree coming down.
He called triple-0, then returned to show police where it happened.
"They were shining torches around and behind the car a man jumped up," he said.
"The police yelled 'Are you okay? Hello' and he actually took off and jumped into a creek and he was only wearing underwear."
Mr Bolch said the weather was poor when the crash happened.
"It's on a horrible bend that's not well signposted and if you're not a local you'd miss it," he said.
He said the driver had gone straight over the edge.
"Looks like he's failed to negotiate the turn and he's probably dropped 100m or so," he said.
He said it was not the first time he had seen a crash in the area.
"About five years ago there was a young gentleman who, very similar, failed to negotiate the corner, actually hit a tree and passed away," he said.
Little girl dies in river tragedy
It comes as the Palmers Island and Yamba communities mourn the death of a 19-month-old girl.
Emergency services were called to Palmers Island shortly after 10am Sunday after receiving reports the child was missing.
Authorities began searching the area and the girl was found unresponsive in the Clarence River about 20 minutes later.
Police say CPR was performed until the girl could be taken to Maclean Hospital, but she was unable to be revived.
Flooding in Clarence Valley
The Clarence River catchment experienced minor to moderate flooding at the weekend.
The Clarence peaked at 4.34m at Prince St in Grafton about 5pm Saturday, while the Orara River peaked near the minor flood level of 5m at Coutts Crossing about midday Sunday.
The weather bureau has since issued final flood warnings for both rivers, with the water sitting below the minor flood levels and falling.
