(CNN) -- After the deadly flooding of 2016, Howard County Executive Allan Kittleman said Ellicott City, Maryland, was reduced to a "war zone" and likened it to the set of a disaster movie. On Monday, Kittleman said the flooding of 2018 was much nastier.
Authorities were still in the assessment stage on a soggy Memorial Day, determining exactly how much nastier. Particularly worrying, Kittleman said, is a 25- to 30-foot-wide hole north of Main Street, where the road appears to have buckled under the weight of the flooding.
"There are a lot of people whose lives are going to be devastated again, and they've been working so hard to come back," Kittleman said. "I can't imagine what they're going through. I couldn't imagine what they went through two years ago, and now it's even worse."
The first concern is people. Emergency responders on Monday conducted 300 rescues -- about 30 of them water rescues -- as they continued searching for Sgt. Eddison Hermond of the Maryland Army National Guard.
Sarah Lopez was at a Mexican restaurant downtown attending a birthday party with Hermond when the flooding began, she said. Hermond left to help a woman rescue her cat. Witnesses returned and said Hermond slipped into the river and was carried away, said Lopez, whose husband met Hermond 20 years ago in the US Air Force.
"(The people with Hermond) saw him go under the water and not surface," police Chief Gary Gardner told reporters.
Hermond, 39, joined the Air Force in 1996 and served 10 years as an airman, the Guard's Col. Charles Kohler said. The Severn native joined the Guard in 2009, and is assigned to Camp Fretterd Military Reservation in Reisterstown. He was not on duty when he disappeared.
'The water was rushing fast'
As rescuers looked for Hermond, there were no reports of deaths or major injuries, Kittleman said. The 2016 flood killed two people, when floodwaters swept away their vehicles.
A major water main broke, and the flooding washed out a sewer line. Gas and electricity have been shut down on Main Street, where water ran through buildings as if it were a tributary of the nearby Patapsco River, which swelled to record levels during Sunday's storms. The river is a major waterway that feeds into the Chesapeake Bay.
Baltimore Gas & Electric said it will survey its infrastructure damage before providing a timeline for restoring services.
Flooding claimed the old courthouse, Kittleman said, and there are homes on the west end of downtown whose foundations and basements are gone.
"A lot of the businesses, the first floors are gone, like they were two years ago," he said.
Max Robinson, whose family owns a kitchen goods store that had to be rebuilt after the 2016 flood, said he went outside to move his car to higher ground when he encountered a local business owner helping a vision-impaired neighbor get to his apartment. The water was ankle high at the time, he said.
By the time they got the man to safety, the water had risen to Robinson's thighs. Cars and trash cans floated by. Robinson realized he didn't have a way to get back into his building. At one point, he thought he might die, he said.
"The water was rushing fast," he said. "I was banging on doors to get in. I think I would've gotten pulled away if there hadn't been an unlocked front door to an apartment building."
And his automobile?
"I don't know where my car is. It was near the flooding in a lot. It's probably gone."
The rains of 2016
Marked by quaint shops in the bottom floors of brick, stone slab and siding-clad buildings, the historic downtown is a major draw in this community of 66,000 about 12 miles west of Baltimore.
Main Street, also known as Frederick Road, was transformed into a waterway over the weekend, as brown water sluiced through town, destroying shops and upending cars. In some areas, the water rose above the buildings' first floors.
To understand what authorities were surveying Monday, it's helpful to know what happened fewer than two years ago.
After 6 inches of rain fell on the flood-prone community in about two hours, residents say the flooding came from nowhere in 2016. In addition to the two people killed, more than two dozen buildings were heavily damaged or destroyed. Residents formed human chains to pluck their neighbors from the high waters.
Kittleman said it was the worst devastation in Howard County in 50 years, but the town rallied around the slogan "Ellicott City Strong" and got to work putting their community back together.
When the rain came Sunday, many residents remained in the throes of recovery. The county was working on stormwater retention ponds and preparing to install additional piping. Money from a Federal Emergency Management Agency grant had just arrived and was slated for repairs and construction, Kittleman said.
"You can't get things done in a year or two," he said. "It just can't happen. And you saw, we get the money from FEMA two years later. That's how it works."
More than 8 inches in 15 hours
The river rose 17.8 feet in two hours Sunday -- to 24.1 feet, a record from the previous high of 23.6 feet. The National Weather Service, which issued a flash flood warning, reported greater Baltimore got isolated rainfall of more than 9 inches. Three to 6 inches was common in the metro area.
In parts of Ellicott City, more than 8 inches fell between 6 a.m. and 9 p.m. Sunday, the weather service said. The eastern portion of the community saw more than 7 inches in that timespan, while the southwestern side of town received more than 5 inches.
Another inch could fall Monday, the NWS said, and though that doesn't sound like much rain, it means trouble for the already saturated ground and burgeoning rivers. Aside from the Patapsco River, there are four other smaller waterways running through and around Ellicott City.
The Howard County Department of Fire and Rescue Services urged residents to evacuate downtown while rescue teams fanned out. They're being asked to stay away from Main Street until authorities can ensure buildings are safe to enter. The Roger Carter Community Center is sheltering the displaced.
'It's just devastating'
Gov. Larry Hogan toured the area Sunday with Kittleman. He lamented the destruction, noting that two weeks earlier, he visited the historic downtown and spoken with business owners about rebuilding.
"The place looked terrific," he said. "It's just devastating because people have their lives tied up in this and went through a heck of a lot and came back and now they're starting all over again."
Hogan declared a state of emergency for Maryland on Sunday. As part of the declaration, the Maryland Department of Housing and Community Development will defer the payments of affected Ellicott City businesses that participated in the 2016 recovery loan program.
Kittleman expressed confidence that Ellicott City can make another comeback.
"We'll be one Ellicott City," he said. "We will be stronger in the future. We really will, folks. This is not a place that gives in. We didn't give in in 2016. We're not going to give in in 2018."
Asked what he'd say to downtown business owners who have doubts about reopening after being hammered twice in 22 months, Kittleman said he sees their side of things.
"I can totally understand what they're saying. If I was in their shoes, I'd probably be reassessing that myself."