Investigators believe a woman in her 20s was killed in the collision. (David Bell/CBC - image credit)An investigation is underway following a fatal head-on crash Friday in southeast Calgary involving an SUV and a semi truck. The Calgary Police Service says the collision happened around 5:30 p.m. in the westbound lane of Peigan Trail S.E., near the 52 Street S.E. The driver of the semi, a man police say is in his 50s, was treated for minor injuries in hospital. Neither speeding, drug or alcohol are considered to be factors in the crash, police say.