Five environmentalists heading to East Palestine, Ohio to provide “environmental support” in Bedford, Ohio after a metal plant mysteriously exploded earlier this week, died in a plane crash in Little Rock, Arkansas.

Local news outlets reported a twin-engine Beech BE20 crashed in a densely wooded area shortly after taking off from Little Rock’s Bill and Hillary Clinton National Airport.

ABC 5 News reported, “All five people were employees at Little Rock-based consulting firm CTEH.”

Per its site CTEH is a environmental consulting company that ” empowers extraordinary teams of experts to help companies, governments, and communities prepare for, respond to, and recover from threats to their environment and people.”