3 shark attacks off Sydney in just over 24 hours; man, boy in critical condition

Three shark attacks in 24 hours leave a man and a 12-year-old critically injured and another boy unharmed at Sydney beaches. Here’s what we know.

Man dies in shark attack at Sydney beach

A man in his 50s was killed by a large shark while surfing at a beach near Sydney, Australia on Saturday.

VIDEO: Florida shark, stingray get into tussle off the coast of Panama City Beach

WATCH: A shark and stingray engaged in quite the tussle last month off the shore of Panama Beach in Florida. A woman was able to capture the moment on camera.

Largest shark ever tagged by research group spotted off Florida coast

Researchers are tracking what may be the largest male white shark ever tagged by OCEARCH, with recent signals coming from off Florida's east coast near Jacksonville.

Scuba divers have 'once-in-a-lifetime' close encounter with great white shark near Catalina

Scuba divers near Catalina had a rare and thrilling encounter with a 15-foot Great White Shark, capturing the moment on video as the shark calmly circled them before swimming away.

Shark attack off Hawaii's Oahu island leaves woman seriously hurt

Also Friday, reported back-to-back shark attacks led authorities to temporarily close beaches to swimmers in Walton County, on the Florida Panhandle.

Shark bites leg off American tourist in Turks and Caicos: report

An American tourist has lost her leg after being bitten by a shark while vacationing in Turks and Caicos, police say.

California swimmer survives shark attack off Pacific coast

A 50-year-old woman is being treated for puncture and laceration wounds after a shark bit her leg at a Southern California beach.

Sharks swimming closer to crowded beaches than previously thought, study says

"We were surprised to find that the sharks we tracked spent so much time near the lights and sounds of the busy city, often close to shore, no matter the time of day," the study author said.

Shark reportedly bites surfer off coast of Santa Barbara

A shark reportedly bit a surfer Saturday afternoon off Santa Rosa Island in a “truly terrifying situation,” the Coast Guard said.