It was another dramatic morning at LAX today. Around 10:30 a.m., a man with a large carry-on bag accidentally set off the bus' on-board fire extinguisher in a Van Nuys bound FlyAway Bus that was just beginning its rounds at Terminal 1, according to Nancy Castles, spokesperson for LAX, in a telephone press conference. Initial reports stated it was an explosion, but the discharge caused a loud sound and the release of a "white powdery substance," prompting the response of the LA Fire Department's hazardous materials team. The arrival lower level lanes were completely closed, but as of 11:50 a.m., two of the five lanes were open. The departure level, airlines and terminals were all operating normal. While there is no passenger count available, there have been no reports of injuries. Update: Traffic for all lanes reopened short before noon. There were 10 passengers on the bus who all exited the bus safely through the front door. The extinguisher discharged near the rear door.