Two firefighters, one police officer and two civilians were hospitalized after being stung by a swarm of up to 40,000 bees in Pasadena, Calif., on Thursday. The swarm occurred outside of the Howard Johnson Hotel across the street from Pasadena City College. Pasadena Fire Department spokeswoman Lisa Derderian tells TIME that the department was the first to arrive to treat a civilian, unaware of the size of the swarm.