A Swiss tourist is in critical condition in South Africa after a minibus knocked a giraffe onto the top of his safari camper, officials said.

The 18-foot tall giraffe was struck Sunday in Kruger National Park by the bus, which was carrying a group of tourists, sending, the Telegraph reported.

The 1,600-pound animal was killed when it landed on the parked camper, which contained the man and his family. It’s unclear why the crash occurred.

“It is not our job to speculate,” parks spokesperson Ike Phaala told the outlet. “We remind all visitors that this is a wildlife park and animals have right of way and… can appear unexpectedly.”

The Swiss camper driver was airlifted to a Johannesburg hospital, where he remained Monday on life support, the Telegraph reported. His wife and two taxi riders suffered minor injuries in the incident.