Oil leaked into the Hudson River on Sunday after a transformer fire and explosion a day earlier at the Indian Point nuclear plant north of New York City, and Gov. Andrew Cuomo said he was concerned about environmental damage.

Cuomo visited the plant for a briefing on Sunday. The governor, who in the past has called for the plant to be shut down because of its proximity to densely populated New York City, also visited the plant on Saturday.

When the transformer exploded, it released oil into a holding tank, which then overflowed, sending oil onto the ground and into the river, Cuomo told reporters on Sunday after he was briefed by emergency and plant officials.