The delays in trains from Stockholm’s central station Wednesday was caused by a bird, Swedish Radio News reports.

The direct cause was a short circuit in an electrical cable. But now Lena Eriksson at the Swedish Transport Administration says that was caused by a bird flying into the overhead cables.

“We try to prevent these things, and you can do it to an extent by putting up things that birds don’t like and discourages them from building nests near the overhead cables,” she says. “But it isn’t easy.”

The short circuit closed down traffic on four different tracks at Sweden’s main...