It has been a few days since the Taal volcano in the Philippines started rumbling. Even as things seem to have mellowed down, many unfortunate creatures remain buried in the ash, testament to the strength of the volcano — even as a full-blown eruption has not taken place.

Another demonstration of that strength is the volcanic lightning captured by timelapse footage: a lightning storm, swirling dark clouds around the volcano’s peak.

Volcanic lightning is a somewhat common phenomenon (common relative to how often volcanic eruptions take place). Volcanic lightning arises from particles of volcanic ash (and sometimes ice) ejected in the atmosphere. These particles generate static electricity within the volcanic plume, triggering a “dirty thunderstorm.” The exact interactions that lead to this phenomenon are not fully known, but the process has been documented since ancient times.

Initially, officials said the plume from the Taal volcano stretched 1km (0.6 miles) into the sky, but has since grown tenfold — and the taller the plume, the more likely it is to generate a storm.

As for the Taal volcano, the Philippine Institute of Volcanology and Seismology (PHIVOLCS) said Wednesday morning that the volcano remains at alert level four out of a possible five, meaning an “explosive eruption is possible within hours to days.”

The volcano is 37 miles (60 km) south of the Philippines capital Manila on the island of Luzon. It began erupting on Sunday, sending ash up to 9 miles (14 km) into the air, prompting large-scale evacuations for thousands of people and covering the volcano’s surroundings with a thick layer of ash.

In addition to the eruption itself, several hazards pose risks to the locals. Volcanic earthquakes have caused fissures on the sides of the mountain, and mudslides caused by rain washing unconsolidated ash can be devastating. There are also concerns about the sides of the volcano collapsing into the lake, causing a tsunami — which can also wreak havoc on the surrounding environment.

In addition, breathing in the toxic volcanic ash (which can carry microscopic shards of glass) can also be harmful.

There are currently half a million people directly at risk from the volcano, and out of that number, only 44,000 have been officially evacuated.

Even if the volcano doesn’t erupt anymore, it has caused considerable damage, coating everything in ash, destroying households and killing animals. The situation remains tense — another reminder that to the immense force that nature can unleash with the slightest of warnings.

This article refers to an ongoing situation and may not be updated regularly.