The Federal Aviation Administration has declined to order US airlines to ground the Boeing 737 MAX 8 after two recent fatal crashes. In a statement, the FAA said investigators have not yet determined whether the issue with the Ethiopian Airlines jet that crashed on Sunday is related to the issue that brought down the same plane operated by Lion Air, an Indonesian operator, last year. The FAA's Continued Airworthiness Notification to the International Community said external reports are drawing similarities between this accident and the Lion Air Flight 610 accident on Oct. 29, 2018. However, it continues, the investigation has just begun and “to date we have not been provided data to draw any conclusions or take any actions." Aeromexico became the first North American airline to ground the planes on Monday but US airlines had not followed as of Tuesday morning. American Airlines, United Airlines (which flies the larger Max 9) , and Southwest Airlines said they were closely watching as investigators try to determine what happened to Ethiopian Airlines Flight 302, which crashed Sunday after departing Addis Ababa. Airlines in China, Singapore, Argentina, Ethiopia, Brazil and other countries have grounded the planes – either voluntarily or because they were ordered to by regulators. European regulators have not yet asked carriers to ground the jets, but UK authorities have grounded them.