Scientist: Poisonous goo.
Chemist: Excessive skin contact with dilute strong acid, mercury poisoning.
Physicist: Electrocuted.
Dr. Toxic: Meltdown.
Astronaut: Rocket explosion (Challenger-like).
Marine Biologist: Bitten by a shark.
Archaeologist: Commited suicide due to forgetting where he left the Chomposaurus Rex skeleton.
Paleontologist: Fell into a hole when digging some fossil.
Zoologist: Bitten by a venomous snake, some wild animal attacked him to death (lion, tiger, etc.).
Computer Scientist: Sleep deprivation due to prolonged use of computer/laptop for software development.
Super Brainz: Losing to what he thinks are the villains. (plants)
Dr Spacetime: Teleporting into a black hole.