NEW YORK (MarketWatch) -- Runways at London's Heathrow Airport are reopening after closing because of an onboard internal fire involving an Ethiopian Airlines Dreamliner 787, built by Boeing Co. BA, +0.04% . In a tweet, the airport said it had suspended arrivals and departures and that no passengers are aboard the parked plane. More recently, officials tweeted that runways are beginning to be reopened. The plane is parked away from a terminal, airport officials tweeted separately. Boeing shares are down 6.4%. In a tweet, Boeing said: "We're aware of the 787 event @HeathrowAirport and have Boeing personnel there. We're working to fully understand and address this."