If it was flying from Amsterdam to Kuala Lumpur then it would have been at cruising altitude over Ukraine ~ 35.000 feet. If it was downed by a military force it will be hard to justify given the altitude. It is also daylight. It may not have gone down due to hostile fire. We don't know yet.
Such a tragedy - no matter what the cause. And will be a real blow to Malaysia Airlines. Pan Am went out of business quickly after the Lockerbie crash.
Prayers to all.