A woman who allegedly was reading a text message while behind the wheel of a car that struck two teenagers in Hatfield Township, killing one of them, has been charged with homicide by vehicle and driving while under the influence of alchohol.

Bail was set Friday at $100,000 for Sarah Derstein, 31, of Lansdale.

On April 26 at 11:34 p.m., Dennis Kee, 15, of Hatfield, was walking with four friends along the southbound shoulder of Route 309 when he and a friend, also 15, were hit by Derstein's 2007 Toyota Corolla.

In a news release officials said "Kee was catapulted over the guardrail and landed in a field 10-15 feet from the roadway." The other victim suffered a broken elbow.

Derstein continued driving, returning to the accident area about an hour later, where she told an officer directing traffic that she had hit something on Route 309. Police then found fresh damage to the front of her car. A laboratory test showed her blood alcohol content at 0.167 - more than twice Pennsylvania's legal limit, police said.

Contact Carolyn Davis at 610-313-8109, cdavis@phillynews.com, or @carolyntweets on Twitter.