KEY BISCAYNE, Fla. -

Police are looking for the driver who hit two cyclists on the Rickenbacker Causeway early Wednesday morning. 

Police said two men were riding their bikes east over the bridge at about 6 a.m. when a car hit both men. The driver fled the scene and left the men injured on the road, police said. 

Cyclist Enda Welsh fractured his ankle in the accident, but his friend, Aaron Cohen, had more serious injuries.  

Miami police detectives snapped photos of a blood-stained bike helmet and the crumpled front tire of Cohen's bike.

Cohen is in critical condition at Jackson Memorial Hospital with severe head trauma. Cohen's wife said he underwent surgery Wednesday morning.

"This guy, he's out there and he knows what he did,” Welsh said. “He didn’t even stop to see. He didn't care." 

Cohen's wife said he is an avid cyclist. He has two children, 3-year-old Lilly and 1-year-old Aiden.

Police believe the suspect was driving a 2009-2011 silver Honda Civic. It is missing is right rearview mirror. Investigators also believe the car may have some hood damage. 

If you see this car or if you have any information about this crash, you are asked to contact Miami police immediately.

This isn't the first time a bicyclist has been hit by a car on the Rickenbacker. Two years ago, prosecutors said Carlos Bertonatti was driving under the influence when he hit and killed cyclist Christopher Lacanne.

The incident prompted community outrage and a petition to county commissioners asking to reduce the speed limit from 45 to 35 mph.

Avid cyclist Bart Sherwood said that didn't go anywhere, and neither did the plans to increase police patrols.

Sherwood said he would like to see more digital signs reminding drivers of the speed limit.

Police said they do enforce the speed limit.

Click here for information on the county's plan to ensure pedestrian and bicyclist safety.