A runaway truck carrying a construction crane smashed into a wall at a Manchester, N.H., day care center playground Wednesday, narrowly missing about 50 children who had just left the area for their morning snack.

“We were seconds away from tragedy,” said Connie Elliott, director of the Alpha-Bits Learning Center.

“Our counselor, I’m talking seconds before it happened, called the children over to have snack … and brought the children closer to the building,” she said.

The driver, Kerry Norton, was able to stop the truck from crashing into the day care center. “If he had not stopped it, it would have crashed into our building, with 300 children in it,” Elliott said.

Norton and his partner were securing a crane on the truck at a construction site at nearby Catholic Medical Center around 10:30 a.m. when it began rolling backward.

Elliott said Norton ran to the cab, jumped in and hit the brakes, but not in time to prevent the rig from smashing a cement wall near the street and a brick wall at the playground.

“Bricks and cement all went flying,” she said, and a storage shed in the playground was smashed, right next to a swing set and monkey bars.

Norton, of Scarborough, Maine, said he and his partner were securing the crane on the truck with chains when the truck and crane, all 140,000 pounds of it, started rolling.

“We’re both standing on the trailer in the back, inside of the crane, and I hollered, ‘The crane is moving,”‘ he said. “So I jumped out. I ran on the passenger side to the truck – and it’s rolling downhill.

“I jumped in, climbed over and tried to get behind the seat as best I could and I just jammed on the brakes,” Norton said.

He estimated the rig might have rolled 30 to 35 feet.

“I really feel blessed that more didn’t take place,” he said.

In all, 130 children, including about 80 preschoolers, were on the playground. The 50 who left the area for their snack were about 30 feet away when the bricks flew into the area, Elliott said.

“I ran to the shed and they said, ‘It’s going to collapse,”‘ Elliott said. “I said there could be children under there. I have to get them out.”‘

But after “a few minutes of panic” they had counted heads, and all the kids were accounted for, and unhurt.

Police are investigating what caused the truck to roll.