At the gas station convenience store where she works in the Baltimore area, Patricia Sisk regularly encounters harried commuters and stressed-out parents in the early morning hours.

But on Tuesday, after the collapse of the Francis Scott Key Bridge about a mile and a half (2.5 kilometers) away, the 82-year-old Sisk instead greeted a steady stream of police officers, emergency personnel and shocked residents.

"It's scary," Sisk, sporting her uniform cap, told AFP as sirens rang out.

"I've seen all this police force and they told me what happened. (...) I feel for the people."

Sisk said several customers "thought it was an explosion. It was just horrible. They were scared."

Rescue teams and police were deployed en masse to the scene in the East Coast port city north of the US capital, blocking roads leading to the bridge, which crumbled into the water after being struck by a container ship.

Authorities said they were looking for six people believed to be missing in the water.

Sisk said she hadn't had the same "creepy feeling" since the September 11, 2001 attacks, which left nearly 3,000 people dead.

"You know, when the towers.... and then you wonder," she said in a calm but worried tone.

  'Panicking and crying' 

 Sisk spent the morning talking about the accident with customers at her cash register. Many were regulars who couldn't get where they needed to go, instead sharing with her videos of the bridge collapse posted on social media.

One of those regulars, 41-year-old Jennifer Woolf, told the harrowing tale of her son's brush with catastrophe.

After a late-night quarrel with his girlfriend, the 20-year-old hit the road. He crossed the bridge once, and then turned out to reconcile with his partner.

"He went back over the bridge a second time and as soon as he got over, (after) three minutes exactly, the bridge collapsed," Woolf explained as she got her morning coffee.

"He came home panicking and crying, like shaking, and I started crying," added the entrepreneur.

"He's still awake. He hasn't gone to sleep either... watching the news, he keeps texting me nonstop," Woolf said, adding that she was praying "for all the families that are going through the tragedy of looking for their loved ones."

  'Never seen that' 

 With his breakfast, soda and cookies in hand, Baltimore resident Paul Kratsas said he had long feared that an incident like Tuesday's bridge collapse could happen.

"Yesterday, actually, I was going to use it," the 59-year-old Kratsas said of the bridge. "When I go over it, sometimes I'm like, 'Man, I hope I hope this thing don't fall.'"

"These ships go in and out all the time," added the man, who came to check out the scene with his wife. "And they usually bring them in with big tugboats."

"Yeah, never seen that happen before," Kratsas said.