Police are trying to determine why a pickup truck crashed into a man and young girl on Temple Street in Whitman Sunday afternoon, killing the man and injuring the girl.

Edward Cordwell, Jr., 38, of Whitman was crossing the street with his girlfriend’s 4-year-old daughter when a pickup truck struck them, police said.

Fire Chief Timothy Grenno was at his home on Temple Street and heard the crash. He said that speeding has been an issue in his neighborhood, adding that “we have frequent motor vehicle crashes on Temple Street,” he said.

The driver of the 2004 Dodge Ram pickup has been identified as Richard C. Brown, 46, of Attleboro, police said.

Police Chief Scott Benton said officers have seized Brown’s phone and are in the process of obtaining a warrant to search his phone history. He said police are also interviewing witnesses.

“There was a yard sale going on on the corner, so there were people around,” Benton said. “It’s kind of a busy intersection.”

Grenno said several neighbors witnessed the crash.

“There were bystanders all over the place,” Grenno said. “A lot of people came out of their doors and stopped their cars and such. There were quite a few good Samaritans.”

The incident happened at 2:03 p.m. at 232 Temple St.

Grenno summoned additional help, including two MedFlight helicopters. Cordwell was bleeding profusely, unresponsive, unconscious, and had life-threatening airway conditions, police said.

“Due to the nature and seriousness of his injuries, he was not stable enough to fly,” Grenno said. Cordwell was taken by ambulance to Brockton Hospital, where he was pronounced dead.

The young girl was unconscious and unresponsive at the scene, but regained consciousness and spoke to Whitman fire officials before she was flown to Massachusetts General Hospital, police said.

The crash is under investigation by Whitman police, State Police, and the Plymouth County sheriff’s department.