HARRISBURG — Democrats have chosen a history professor as their candidate to run to replace a four-term Pennsylvania state senator who resigned last month after being arrested on child pornography charges.

Lebanon Valley College associate professor Michael Schroeder was selected Sunday for the Jan. 14 election for the 48th state Senate seat.

He will face Lebanon County District Attorney David Arnold, who received the Republican nod in Saturday's nomination conference.

The election in the heavily Republican district is being held to replace former senator Mike Folmer, who resigned after authorities alleged that they found two images of child pornography on his cellphone.

Folmer, who hasn't commented, waived his preliminary hearing Friday. His resignation left the 50-seat Senate with a 27-22 Republican majority.

ALLENTOWN— Authorities say an early morning house explosion in Allentown blew off the front of a row home and led to a fire that spread to nine other homes, but no serious injuries were immediately reported.Allentown fire officials said the blast was reported at 3 a.m. Sunday. One person initially unaccounted for was later found safe. A firefighter was treated for a shoulder injury.Officials said more than two dozen people were displaced by the blaze.