Today marks the 30th anniversary of the Chernobyl disaster in then-Soviet Ukraine, and multiple church services are being held across the country.

In the town of Slavutych, where people were evacuated following the accident, people laid flowers and lit candles. Similar services were held in the capital Kiev to remember the firefighters and workers who died in the disaster.

In the town of Slavutych, where people were evacuated following the accident, people laid flowers, and lit up candles.

The Chernobyl disaster was the most serious nuclear accident in human history. The initial explosion in April 1986 was caused by a botched safety test in the fourth reactor of the atomic plant. Thirty-one were killed immediately and tens of thousands were forced to flee because of the nuclear fallout.

It also exposed millions to dangerous levels of radiation to the air. Until today, the death toll of those killed by radiation-related illnesses, such as cancer, is subject to debate.