Answer

In Jain tradition, the commonly mentioned disaster was the ruin of Hastinapur: a swarm of red locusts destroyed the crops, and a flood in the Ganga further devastated the city. ( jainpuja.com)

Explanation

This event is described in Jain accounts of Hastinapur’s decline. If this is the incident you meant, it is the disaster most often associated with that long historical period before Bhagwan Parshvanath’s time. ( jainpuja.com)

Takeaway

So, the answer is: a severe locust attack and flood. ( jainpuja.com)