A thunderstorm hit the Zagreb area around 2 a.m. tonight, causing many sleepless nights for residents in the area. One Twitter user described the storm as an “apocalypse,” while another said he didn’t expect to be woken up by thunder at 3 a.m.

It was two hours after midnight when the storm hit, and one Facebook user wrote that he was startled by the loud thunder and initially thought it was an earthquake. The announced change in weather and cyclones moving over the area brought with them thunder with strong shocks, according to Dunja Plačko Vršnak from DHMZ, who said on Good morning Croatia that this weather is appropriate for the time of year.

The strength of the thunder was evidenced by a tweet from EMSC, which reported that many people thought it was an earthquake due to the rumbling and shaking heard in the northern part of Zagreb. One user from Stenjevac added that they felt a strong sound during the storm, but overall it seems like everyone survived unscathed.