SEPTA investigators are trying to determine whether a trolley driver fell asleep and thus caused a collision of two Route 11 trolleys in West Philadelphia last week.

Fourteen passengers were hurt when one trolley rammed the rear of another near 72d Street and Woodland Avenue about 8:30 a.m. June 3, SEPTA chief press officer Jerri Williams said.

One passenger's arm and neck injuries were serious enough to require hospitalization, Williams said. The operator of the rear trolley "claimed injury" and was taken to the Hospital of the University of Pennsylvania for treatment, according to SEPTA's report of the accident.

No mechanical defects were found with either trolley, and "the personnel investigations are ongoing," Williams said. She said "no determination has been made that he was asleep at the time. ... No witnesses have said that, and there are no video cameras" on the trolleys. SEPTA rules require trolleys operating within 20 feet of each other to maintain a speed of no more than 5 m.p.h. The operator of the rear trolley remains on paid injury leave. - Paul Nussbaum