Ellicott City, Maryland was devastated in 2016 by a flash flood — the type of event that many people said happens only once in one thousand years. But now, disastrous flooding has happened again. More than 300 residents have been evacuated, and on Sunday afternoon, there were over one thousand calls to 911.

Governor Larry Hogan declared a state of emergency and said, “They say this is a once-every-thousand-years flood, and we’ve had two of them in two years.” Seven to nine inches of rain poured down on Ellicott City, about 10 miles west of Baltimore. Main Street transformed into a rushing, muddy river. Cars were swept down the street like toys. Army National Guardsman Eddison Hermond died after trying to help a woman and her cat.

Related: California’s wild extremes of flooding and drought will only get worse as the planet warms

Slate reported Ellicott City is a 250-year-old river town that’s been hit with flooding in the past. But the 2016 flash flood and this recent one have been different than previous floods. Typically, the Patapsco River rises and causes flooding. With these flash floods, the Tiber and Hudson tributaries — one of which runs beneath Main Street — overflowed, according to a 2016 Baltimore Sun investigation.

University of Maryland Baltimore County geography professor Jeffrey Halverson told NPR, “[Ellicott City] is heavily paved, there’s lots of narrow streets that act as very rapid conduits of water — so the [2016] flood was as much about the nature of the underlying land surface as it was the large amount of rain falling from the sky.”

“There are a lot of people whose lives are going to be devastated again, and they’ve been working so hard to come back,” Howard County Executive Allan Kittleman said. “I couldn’t imagine what they went through two years ago, and now it’s even worse.”

Via Slate, NPR, The Baltimore Sun (12) and CNN

Image via MarylandGov Pics and Preservation Maryland