Scuba diving is a sport where people with aid of artificial breathing equipment dive deep into the sea. As you descend deep into the sea you are subjected to extremities of pressure. Rising too quickly from depths can cause the blood vessels to rupture and chances of air entering into the system become very real. This is also one of the reason for air embolism to occur.
Trauma due to the explosion:
If a human body is exposed to a sudden explosion of energy like in a bomb blast, then it causes rapid and widespread rupturing of blood vessels and open wounds. These open wounds can land up as an avenue for air embolism to occur.