At 6:12 a.m., Kiev-bound, Ukrainian International Airlines Flight 752 took off from Tehran’s Imam Khomeini International Airport. Less than five minutes later, the Boeing 737-800 was a smoldering wreck. All 176 passengers and crew members perished. Among the dead were 82 Iranian citizens, 63 Canadians, 11 Ukrainians, 10 Swedes, four Afghans, three Brits and three Germans. Some of those on board had dual citizenship.

Almost immediately following the tragic incident, Iranian aviation authorities made two announcements. First, they declared that the plane crashed because one of the engines caught fire. Second, they said that they would not transfer the black boxes, which contain critical data, to Boeing officials, National Transportation and Safety Board (NTSB) officials or to any Americans. On Thursday morning, Iranian officials announced that they had retrieved the black boxes but that they were severely damaged, and data was missing.

There is ample reason to conclude that the Iranian authorities are lying through their teeth on this one and are engaged in a massive and pernicious cover-up. Preliminarily, all the evidence points to the fact that the plane was actually shot down by a Russian manufactured, Iranian anti-aircraft missile, though Iranian officials have dismissed this allegation as “scientifically impossible.”

There are a number of factors that have led experts to conclude that this was in fact the case. First, Iranian civil aviation authorities concluded rather hastily that engine failure led to the aircraft’s demise. Professional aircraft crash investigations are meticulous, painstaking and time consuming, taking weeks, months and sometimes years to draw definitive conclusions. Thus, the Iranian announcement coming just hours after the crash was not just reckless and irresponsible, it appeared to be calculated.