One tree was all it took. Around 12:30 p.m. on Thursday, a
wayward trunk tumbled over onto a major transmission line in
Puerto Rico’s still-fragile electrical grid and cut power to
roughly 840,000 customers, affecting more than half of the
Officials from the island’s electric utility company – PREPA —
said the accident occurred in the region of Cayey, where crews
were working to restore power to people still waiting nearly
seven months after Hurricane Maria. Increasingly, that work
requires clearing away heavily forested mountainsides to gain
access to the large utility poles that carry transmission lines
from one mountain peak to the next.
It was during that kind of work that a tree falling toward the
ground made contact with the power line instead. One worker,
employed by a PREPA subcontractor, was hospitalized with burns
to his hands, though officials said he was in stable condition.
It would seem remarkable that a single tree could plunge more
than half of the commonwealth’s population into darkness. But it
was so, and PREPA even tweeted a picture of the tree. Karla
Iglesias, an engineer who has worked on Puerto Rico’s electrical
grid, said it has everything to do with the fact that the line
the tree made contact with – known as line 50900 — connects two
of the island’s main power plants, Palo Seco and Aguirre.
“This line was coming out of one generation plant and connecting
to another generation plant. So when the tree hits that line,
it’s going to interrupt a major flow of current,” Iglesias said.
“Imagine that you have those Christmas lights. If you break the
first one, the rest aren’t going to work. It’s going to break
PREPA officials said they were working to restore power as
quickly as possible, and some communities had already come back
online by late afternoon. But officials said full restoration
could take as long as 11 hours.
In some places that have had their power back for months, like
the capital, San Juan, the outage was a humbling reminder that
the restoration is not yet complete in more remote parts of the
island, and that one mistake still has the ability to ripple
back to the island’s most populated centers. In places that only
recently got their power back, the outage was a frustrating, if
not totally surprising, setback.
“When you went five-plus months without power,” tweeted Jozyel
Manuel Rivera, “a few more hours or a day isn’t going to kill