Police are investigating after a man shot a couple, killing the man and wounding the woman, before shooting himself at the Downtown Aquarium in Houston on Thursday night. The attack happened shortly after 8 p.m. on the second floor of the restaurant. The couple were seated at the bar having dinner when the man approached them and opened fire. Afterwards, he fatally shot himself. The woman is hospitalized in stable condition, but her companion died at the scene. Police are trying to figure out whether the shooter knew the victims.