A malfunction hits the bunker and opens the cryo pod too early but a deadly infection hits one of the staff members. It grows to the other staff. But the door into the cryo pods is locked. Lucky another person from a cryo pod is an engineer. He hacks into the control panel and opens the door. When they came out, they saw all staff members were dead. All members ran quickly to the armour and grabbed some weapons. When they got the the main headquarters of the bunker, they looked at the main computer. It seems like raiders hacked the system but by accident opening the cryo pods. But the cause of the infection was unknown... Next day. They saw that some weird moss growning on the metal. They burned it with gas and tried to get out of the bunker.
Yeah... I hope this will become useful.