who will shoulder the obligation in the vehicular accident?

I am the investigator of the recent vehicular accident involving one(1) unit of mini dump truck loaded with sand and gravel. had malfunctioned and parked the said mini dump truck at his lane of national road. it was not able placed at the shoulder of the road. and with using a banana leaves as their temporary eARLY warning device. and later, there were two (2)single motorcycles coming behind of the said truck and the leading motorcycle with two persons on board bumped at the rear portion of the said mini truck. while the following motorcycle overrun the said two persons lying of the road. who are liable in this incident?

investigator, you are a police officer, sir? or adjuster?

how many lanes was the road? the truck was in the middle, not at the shoulder? even partially?

Hi! I'm just a concerned citizen trying to help. In my point of view. If the mini driver admits that they placed the banana leaf on the road as an early warning device then they are liable for the accident. First, early warning device should be visible. In this case, it wasn't visible instead it became a trap to other vehicles.

But I maybe wrong because I don't know the whole story. Maybe if you can determine how fast the motorcycles are going then it will be a good start.

I guess it's good to determine the "proximate cause".. why that accident happened after all.