VOLKMARSEN, Germany (Reuters) - Manuela Mattner says she is lucky her five-year-old son was unhurt on Monday when a man rammed his car into a carnival procession in the western German town of Volkmarsen simply because his father pulled him away from the speeding vehicle.

“If my ex-husband had not reacted so fast, my son would be in hospital or maybe dead,” said Mattner, dressed in a black and white pirate costume with gold lining as she walked out of a bar near the site where 30 people were injured.

“He called me to tell me a car had driven into the parade and that they are both fine and that my son was crying and wanted to see me,” added the 40-year-old nurse. “The driver clearly hates carnival but we love it.”

As night fell on this town of 7,000 people, residents were still wondering what had sparked the rampage on “Rose Monday,” a day of festivities ahead of the Christian season of Lent marked by street parades featuring comical and satirical floats.

German authorities say a 29-year-old German man had been arrested on suspicion of attempted murder and that the motive for his rampage remains unclear. A third of those wounded were children.

Police cordoned off the scene of the rampage as forensic experts gathered evidence. A few carnival revelers walked in an out of bars in the town’s medieval center. Neighbors leaning over window sills exchanged discussed what had happened.

“I was at work and I got a message on Facebook messenger saying a man drove his car into people in Volkmarsen,” said construction worker Johannes Peter, who was drinking a beer on his window and talking to his neighbor across the road.

“My first thought was ‘this is a terrorist attack,’” said Peter. “Luckily it wasn’t but what happened is shit.”

In 2016, a Tunisian man with Islamist militant ties plowed a truck into a Christmas market in Berlin, killing 12 people.

At an Italian restaurant near the rampage site, owner David Bufo pointed to half a dozen red hats stacked behind the bar.

“We usually give them to guests who come without a costume,” said Bufo, who came to Volkmarsen 32 years ago. “But today no-one is in the mood for it. We’re just sad about what happened.”

It is a feeling shared by carnival revelers who hit the town’s bars in the belief they could win the day.

“People drank, we drank, but it wasn’t fun,” said Oliver Muetze, Mattner’s boyfriend who works at a tyre factory in the neighboring town of Korbach. “Usually, we dance, we sing and everyone is happy. Not tonight.”