(CBS) -- Puerto Rico National Guard specialist Ricardo Rivera is on the front lines of what's going to be a very long mission.
"We're trying to rescue people in the most safe way we can, but there is still danger"
He's spent the last two days wading through Maria's floodwaters to get people to safety.
"This is really worse than expected"
Across the island, flooding is widespread, homes are crushed, there is no power, no running water, and, except for parts of the capital city, no communication.
"Right now we don't have any communication. All cell phones and internet lines are dead. That's the worst part."
That's making for emotional reunions with loved ones.
Earlier today we spoke with San Juan's mayor.
"The Puerto Rico and San Juan you lived in a couple of days ago is nonexistent so you're going to be impatient. I am concerned about them losing their lives. This is a life or death situation. We're not being dramatic."
Getting the island's ports back open to receive more emergency supplies is a top priority.