The situation I'm considering is as follows:
A large research vessel with a crew of about 100-200 attempts to land on a potentially habitable planet, but something goes wrong during the descent. A few crew members who happened to be close to the escape pods managed to escape the ship and land nearby (about 100-200 meters).
I would like the survivors to be able to investigate the crashed vessel, but they should find everyone dead or missing. The vessel should only have minor damages, implying little atmospheric burn-up; presumably because the descent complications happened closer to the planet's surface. I also want the ship to eventually explode, perhaps due to a nuclear reactor meltdown. This could happen days later, giving the survivors some time to explore the ship.
I'm wondering what could have happened to the ship during the descent that would:
- Leave the vessel relatively intact.
- Kill or "remove" the crew.
- Leave the survivors unharmed in their escape pods.
- Be undetectable from orbit because the crew of a scientific research vessel should know better.
- Potentially be the cause of the ship exploding, though it could be assumed that the reactor meltdown is caused by the physical impact of the ship against the planet.
Ideas I was considering include:
- An electrical disturbance, such as an undetectable storm or an abnormality in the planet's ionosphere (?) that killed the crew by electrocution, but the escape pods weren't struck. Though, this seems too "convenient".
- A gravitational disturbance that violently shook the massive ship, killing the crew, but had little effect on the small escape pods.
- If there could be no effective "natural" explanation, I could resort to alien interference, such as an advanced weapon. Though I'm unsure if I want there to be intelligent life inhabiting the planet.