PORTLAND, Ore. (KOIN) — Four people have drowned in the Sandy River in July alone and none were wearing life jackets, officials said.

During the summer, rivers become popular places for families to visit. First responders say that while rivers may look calm on the surface, people should never underestimate the water current and the cold temperatures.

“Always have a flotation device on you at all times — personal flotation device — and also be cautious of where you are picking and choosing the recreate in the river,” said Sgt. Brian Gerkman with the Multnomah County Sheriff’s Office.

Emergency crews have responded to three major water rescue calls along the Sandy River so far this month. A father and his 7-year-old daughter drowned Tuesday evening at Dabney State Park outside of Troutdale. Deputies said neither person appeared to have been wearing a life jacket.

“Dealing with the situation last night — it’s one of the worst cases you can imagine,” said Gerkman. “I have a 7-year-old at home and I just can’t fathom that loss that the family is going through and it does have an impact on the first responders.”

Drownings are largely preventable if swimmers wear life jackets.

At Glenn Otto Park on the Sandy River, lifeguards are on duty seven days a week from 10 a.m. to 8 p.m. through Labor Day. River rescue technicians like Drew Fox help keep people safe by checking out life jackets in all sizes to those who need them, from infants to adults.

“If you are uncomfortable around water and are not a good swimmer, please wear a life jacket always keep an eye on children around the water; you can have a buddy system,” Fox said. “Wear a life jacket if you are in or around the water.”

Life jackets are also available at Dabney State Park and High Rocks Park on the Clackamas River.

Lifeguards say people should avoid hazards along rivers like rocks and water that is swift-moving, deep and cloudy.

“If you are not a trained river rescue technician, I would not recommend going in and saving somebody. Call 911 immediately,” Fox said.

“For parents, if you start to see your child start to struggle, just know it’s not going to be as easy pulling them out of a swimming pool. They will be panicking, your adrenaline will be up and you will be in cold, quick-moving water. It’s just very very difficult to save even a small person when they are in panic mode,” said Gerkman.

It’s also important to ensure proper fit when wearing a life jacket — something lifeguards can help with.