There was a lawsuit a few years ago by Walmart about panels installed by SolarCity in the early 10s. During this time the company was facing financial issues (their model was leasing panels), so did a lot of cost cutting.

The main causes of PV fires are arcing due to poor installation, e.g. loose connections or damaged components. PV is not like household mains power where you have high current for a few minutes (e.g. turning on a kettle), it's like that for hours at a time. You need to be much more careful.

On a residential PV install, each 'string' from the panels to inverter could easily be 10 or more amps at peak output.